Dinner in the afternoon may be key to a slimmer body.
A form of intermittent fasting that requires people to eat all of their meals earlier in the day appears to be a “powerful strategy” for reducing hunger and losing weight, a new study has confirmed.
It does so by curbing appetite rather than burning more calories, researchers reported Wednesday in the journal Obesity. A longer fasting period also prompted obese people to dip into their fat reserves, leading them to burn more fat, said Courtney Peterson, the lead author and an assistant professor of nutrition sciences at the University of Alabama at Birmingham.
“When we’re trying to design weight-loss programs for people, if we can find strategies that either make it easier for people to cut more calories or to burn more fat, that’s a huge win,” Peterson told TODAY.
“If we can find ways to lower that hunger, people are more likely to be more successful with weight loss and keeping it off.”
- 2 co-workers try intermittent fasting for a month – see the results
- Same calories, different eating windows
- Tips for trying it yourself:
- The Plan: Working Up to 18 Hours of Fasting
- Day 1: Starving by 8:30 A.M., Then Panic-Eating Lunch
- Day 2: Less Hunger Pains, More Major Headaches
- Day 3: Ordering Out — And Skipping the Burger
- Day 4: Drinking More Water Like an IF Pro
- Days 5-7: Hitting the 18-Hour Fasting Mark
- The Results: Mostly Into the Mediterranean Diet
- Intermittent Fasting For Women: A Beginner’s Guide
- Heart Health
- Weight Loss
- It May Help You Eat Less
- Other Health Benefits
- The backstory on intermittent fasting
- Intermittent fasting can help weight loss
- Intermittent fasting can be hard… but maybe it doesn’t have to be
- So, is this as good as it sounds?
- 4 ways to use this information for better health
- Should Women Do Intermittent Fasting?
- What is intermittent fasting?
- Intermittent fasting benefits
- Should women do intermittent fasting?
- What Fit Women Need to Know About Intermittent Fasting
- A guide to 16:8 intermittent fasting
- 5 Reasons You Haven’t Seen Intermittent Fasting Results, According to Nutritionists
- What are the benefits of intermittent fasting?
- Why haven’t you seen intermittent fasting results while following the diet?
- You chose the wrong eating window.
- You aren’t eating enough calories.
- You’re eating the wrong foods during your window.
- You’re forgetting to drink water throughout your intermittent fasting diet.
- You’re overtraining during the diet.
- 12 Lessons Learned from 1 Year of Intermittent Fasting
- Kathleen’s 21 Day Water Fast Journey @TheLifeCoPhuket
- Water Fasting: Benefits and Dangers
2 co-workers try intermittent fasting for a month – see the results
Nov. 8, 201805:40
Same calories, different eating windows
The study compared how people’s bodies responded to eating three meals a day, but on two different eating schedules:
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- Early time-restricted feeding — the intermittent fasting strategy — which only allowed participants to eat during a six-hour window between 8 a.m. and 2 p.m.
- Typical American mealtimes, which allowed eating during a 12-hour window from 8 a.m. to 8 p.m.
Eleven overweight and obese adults were randomly assigned to follow one of the schedules for four days, then the other for the same amount of time. They ate the same number of calories per day — enough to maintain their weight — on both plans.
After each regimen, the participants spent a day in a respiratory chamber that measured how many calories, carbohydrates, fat and protein they were burning. They also rated how hungry or full they felt every three hours, while blood tests measured their levels of hunger and satiety hormones.
Courtesy The University of Alabama at Birmingham
It turned out those who were fasting for 18 hours a day and finished eating by 2 p.m. had lower levels of the hunger hormone ghrelin and higher levels of the satiety hormone peptide YY. Early time-restricted feeding also tended to lower people’s desire to eat and boosted their fullness across the day, though it didn’t affect how many calories they burned.
In another benefit, the fasting regimen appeared to boost metabolic flexibility, or the body’s ability to switch between burning carbs and burning fat for fuel. That’s an important finding because obese people often have trouble burning fat, Peterson said.
Previous research has found the 16:8 diet, where people fast for 16 hours a day, but are free to eat whatever they want in the other eight hours, helped obese individuals lose weight and lower their blood pressure.
“This study helps provide more information about how patterns of eating, and not just what you eat, may be important for achieving a healthy weight,” said Hollie Raynor, professor of nutrition at The University of Tennessee, Knoxville, in a statement. She was not involved in the research.
The authors can’t for certain say whether the appetite-lowering effects are coming from timing meals to the body’s internal clock — which provides peak blood sugar control and energy to digest food in the morning — or the extended fasting, Peterson said. Her best guess was that they were primarily produced by the extended fasting.
Peterson herself follows a similar eating schedule: “I feel a little blissed out when I do it. I can’t explain why,” she said.
Tips for trying it yourself:
People who are “hyper-motivated” can try a six-hour eating schedule that ends at 2 p.m., but researchers believe an eight-10 hour eating window that ends between 4-7 p.m. is a much more realistic target, Peterson noted.
When she asked people how they tolerated the 8 a.m. to 2 p.m. plan, they told her the fasting period wasn’t that bad, but the difficult part was stuffing all of the day’s calories into six hours. “They felt so full — they said it felt like eating Thanksgiving dinner every day,” Peterson said.
Women in particular might need to do a slightly shorter fasting period because they start to burn through fat a little faster than men, so it may be a bit more difficult for women to follow a super-long fast, Peterson added.
It takes your body and hunger patterns about two weeks to adapt to new schedule of eating. “In the beginning, it may be a little bit more challenging… but after you get over that hurdle, it should be easier,” she noted.
The night I realized I always need to carry snacks with me to stave off hangry spells, my sister was discussing the panel on sexual harassment and assault we’d just attended when I turned to her and said, “I’m sorry, I just can’t with this conversation right now” in a voice that didn’t sound sorry at all. She got this look on her face; the only way I know how to describe it is a “tuck your tail between your legs” look.
Ashley and her husband in Iceland. Ashley Edwards Walker
I’d seen it before. Whenever I’d go too long between meals, low blood sugar transformed me into a character much more frightening than the ones in those Snickers commercials. Some people can keep smiling as their stomachs grumble. I am not one of those people.
But I am a person who likes to try new things, especially when it comes to diet and exercise: Whole30, dry January, aerial yoga, trapeze, the list goes on. So when my editor asked me if I’d be game to try trendy intermittent fasting, or “IF,” for one week, it was a quick yes.
Multiple Sclerosis runs in my family, and I’d read fasting can help quell some of the inflammatory symptoms. (I don’t have it, but figured the info would be helpful). Plus, it’s the diet that Jimmy Kimmel used to lose all that weight, and I too am always trying — okay, talking about trying — to drop 10 pounds. So, while I knew there was a decent chance that my husband would be on the receiving end of at least one hunger-induced meltdown, I decided to go all in.
The Plan: Working Up to 18 Hours of Fasting
To get started, GH hooked me up with Jaclyn London, MS, RD, CDN, Nutrition Director at the Good Housekeeping Institute, to give me the low-down. She confirmed that while there are some claims that intermittent fasting can benefit your health and promote weight loss, the data pool is pretty small.
“My hesitation in recommending the diet overall is that research is pretty limited,” London told me. “There have been some human studies linking IF to reduced cognitive decline in at-risk populations, improving markers of oxidative stress, and weight loss. But for the most part, larger-scale studies have found that there’s virtually no difference between alternate-day fasting and simply restricting calories daily.”
There are three main approaches to IF: time-restricted fasting, where you limit your eating to a set time every day and fast for the other 12 to 18 hours; modified fasting (a.k.a. the 5:2 diet that Kimmel follows), where you eat just 25% of your recommended daily calorie intake two days per week and eat normally otherwise; and alternate fasting, where you switch between periods of consuming zero-calorie foods and beverages and actually eating.
London recommended I go with the time-restricted fasting since you can start small and work your way up. Since the cognitive benefits are what I was most interested in, she encouraged me to focus on eating a Mediterranean-inspired diet full of nutrient-dense fruit, veggies, lean protein, whole grains, and healthy fats versus processed foods. “People follow all sorts of different eating styles on ‘feast’ days,” she told me, “but Mediterranean-style eating plans have the largest body of evidence to suggest both weight loss or maintenance and cognitive benefits for the long term.”
Food restriction is like a road trip: When you can’t use the bathroom, you instantly have to pee.
We decided I should start my fasting period at 15 hours, which meant on the first day I could eat between noon and 9 p.m but drink zero-calorie beverages at any point during the day. That didn’t feel particularly restrictive, especially since I’ve never been a big breakfast person and typically only have coffee and a smoothie by noon. But what I learned is that food restriction is like going on a road trip: You don’t think you need the bathroom, but the second you realize you won’t have access to one for a while, you instantly have to pee.
Day 1: Starving by 8:30 A.M., Then Panic-Eating Lunch
That first day I woke up at 6:30 a.m. Two hours later, I was famished. My husband makes smoothies for us every morning (usually a combination of spinach, kale, frozen pineapple, banana, ground flax seeds, and this superfood green powder he gets at some healthy place) and I was basically drooling as I watched him down his before work.
Right away, I noticed I felt especially tired and unfocused. For one thing, it took me three hours to write something that normally would take one because my mind kept drifting off to what I was going to eat later. Also, my stomach was literally growling and I got a pretty annoying headache, something that happened again and again during those first couple days.
Traumatized from how hungry I’d been before, I made myself finish the veggies.
One thing that helped me get through the mornings was coffee. I usually drink two or three cups, with a little creamer. (I know, I know, almond milk is so much trendier/better for you, but it tastes like nutty water to me.) Since I was fasting, London advised I switch to half and half because it’s harder to overdo. She also suggested not adding anything at all, but I just couldn’t swing drinking it black.
When I was finally in the clear to eat, I threw open my cupboard and panic-ate two handfuls of granola just to get something in my system. I thought keeping my smoothie as my first meal would be no big deal given that “lunch” wouldn’t be far behind. Big mistake. Huge. When you haven’t eaten for 15 hours, an 8-ounce blend of kale and fruit just doesn’t cut it. From that moment forward, I started planning a list of hearty “breakfast” options to replace it.
I decided to go a little café near my apartment for lunch and emailed London a couple items from the menu to get her opinion. She picked a bowl that had black and brown rice, tahini spread, roasted fennel, sweet potato, charred kale, pickled beet, a soft-boiled egg, and tamari dressing. I’d never had it, and it was super delicious and filling. In fact, I started to feel full about halfway through but, traumatized from how hungry I’d been that morning, I made myself finish the veggies to stave off any additional hunger pains. Afterward I felt like a new woman!
London helped me pick a filling lunch at a nearby cafe: black and brown rice, tahini spread, roasted fennel, sweet potato, charred kale, pickled beet, a soft-boiled egg, and tamari dressing. Ashley Edwards Walker
Unfortunately, that feeling didn’t last. When I went to hot yoga that evening, it became clear that I was still very unfocused and low-energy. First, I lost the key to my locker and needed help looking for it. Then I forgot my coat not once, but twice. And I usually take every opportunity to flow through my vinyasa in class, but that day I found myself coming down from planks and spending more time in child’s pose than I’ve ever done before.
I was wiped by the time dinner rolled around, so I went super on-the-nose and ordered Mediterranean food: grilled chicken, Greek salad, rice, hummus, and whole-wheat pita. It was delicious and I went to bed that night feeling full, but not overly stuffed the way I sometimes feel when I don’t eat as healthfully.
Day 2: Less Hunger Pains, More Major Headaches
The next day was another 15-hour fasting day, but I woke up around 4:30 a.m. and couldn’t fall back asleep, which made for verrrry long morning of not eating. The good news is I learned from my mistakes and had my leftovers from dinner first instead of the smoothie. That solved the problem of my growling stomach, but the headaches and spacey feeling were still there.
For dinner that night, my husband made homemade whole-wheat pizza with lots of veggies and a teeny amount of cheese. I also had a glass of red wine. All of it was London-approved. She said the trick to drinking wine while doing IF is to not overdo it, since having more than a glass or two could make me dehydrated and trigger feelings of hunger, not to mention lose the willpower to avoid late-night snacking. I made sure to finish the glass by 9 — so not a problem.
Day 3: Ordering Out — And Skipping the Burger
Heading into the weekend, I upped the fasting to 16 hours on Saturday and 17 hours on Sunday. I knew I’d eat at least a couple meals out, so London advised me to order entrees that were at least 50% vegetable-based with some lean protein, healthy grains, and fats thrown in to keep me full. This made the plan very easy and simple to adhere to.
When my husband and I ate out for dinner, I ordered a responsible salad … with a side of lobster mac’n’cheese. Ashley Edwards Walker
On Saturday morning I made my own breakfast bowl with kale, cherry tomatoes, avocado, two eggs, and two slices of bacon. For dinner that night, my husband and I tried a new restaurant. Everyone around us got the burger, which is probably what I would have chosen had I not been doing this plan. Instead, I ordered an arugula, fennel, and tomato salad and my husband got the crab cake sliders. We also got a small plate of the lobster mac’n’cheese, and I used the “I’m on a Mediterranean diet” excuse to eat most of the lobster since London suggested I eat more seafood. (I don’t like fish, so this seemed like a win-win to me.)
Day 4: Drinking More Water Like an IF Pro
On Sunday we brunched at a Mexican place, and I passed up what would have been my usual go-to (tacos!) in favor of a eggs benedict-like entree that came with salad and potatoes — the closest thing to a vegetable-based dish on the menu. Later, I snacked on green pepper slices dipped in hummus, and ate leftover veggie pizza and a kale side salad for dinner.
No tacos for brunch. Instead I got the breakfast version of eggs and potatoes. Ashley Edwards Walker
Even though the daily headaches were still persisting, I felt like I was finally getting the hang of things. I asked London about them, and she encouraged me to drink more water. “The point of this type of fast versus others is that you’re not required to skip non-caloric beverages,” she explained. “Drinking tons of water, seltzer, and unsweetened caffeinated beverages all ‘count’ toward your daily hydration needs.”
Days 5-7: Hitting the 18-Hour Fasting Mark
Over the remaining days I increased the number of fasting hours to 18. It honestly didn’t feel like a huge adjustment since I’d been working up to it, but it did mean I could only eat between 2 and 8 p.m., not a lot of time to fit in three meals. On most days my first meal was a kale salad with cherry tomatoes, avocado, and grilled chicken tossed in olive oil and lemon juice. I’d have my usual smoothie or an apple with peanut butter and granola a few hours later if I was hungry.
A homemade dinner of zucchini noodles, shrimp, and sautéed chard near the end of my IF week. Ashley Edwards Walker
Then not long after that it would be time for dinner. One night I made zucchini noodles and broccoli tossed with pesto, topped with shrimp, and served with a side of sautéed chard. Another night I did grilled chicken with brown rice and veggies. One time I did go totally off the rails and order a chicken sandwich with fries. “Totally fine,” London told me when I confessed what I’d done. “The point is that most of your choices are veggie-heavy, which makes the occasional indulgence all that much easier to have and appreciate. Plus, potatoes are a vegetable!” Best news ever!
The Results: Mostly Into the Mediterranean Diet
I felt good at the end of the week, but didn’t lose any weight. Ashley Edwards Walker
At the end of the week, I definitely felt lighter. When I weighed myself, however, the scale stayed exactly the same — down to the tenth of the pound. I also checked my measurements and apart from losing a quarter of an inch around my waist, there were no other differences in terms of my physical appearance.
I also didn’t see any improvement in my cognitive abilities. By mid-week the fogginess and headaches had subsided, but who’s to say whether it was better hydration, my body was acclimating to the plan, or a legit benefit of the fasting? I think I’d have to do IF for more than a week to get the answer to that question, and that’s not something I’m particularly interested in doing.
London confirmed as much. “The ‘brain fog’ that comes with fasting is one of the main reasons why RDs like me aren’t so quick to recommend it,” she said. “You can’t drive a car without gas, right? Having some food to fuel yourself properly for the day is ‘feeding’ your brain too. Since the cognitive benefits of fasting are mostly linked to long-term neurological benefits, not necessarily immediate ones, there’s definitely an adjustment period.”
The biggest personal benefit for me was sticking to a (mostly) Mediterranean-style of eating. Filling up half of my plate with veggies before anything else led to me making smarter food choices overall, especially when I ate out. And because I chose more nutrient-rich foods, I stayed fuller longer, making the mornings when I couldn’t eat at least bearable.
If you’re considering trying IF, London suggests starting small. “I’d encourage you to keep it as simple as possible,” she said. “Experiment with an ‘early bird special’ for dinner, close your kitchen once you’re finished, aim to get more sleep overnight, and sit down for a full breakfast at your usual time tomorrow.”
There’s no shortage of diet plans out there: Every one from paleo to keto to Whole30 purports to be a life-changing way of eating. But intermittent fasting, another trendy “diet,” has been growing in popularity, and it’s less about what you eat, and more about when you eat it. Maybe you’ve heard buzz about it in your running club, or you know a friend who tried it to lose weight, and you’re curious about it yourself. Here’s a full breakdown on intermittent fasting for weight loss.
What is Intermittent Fasting?
“Intermittent fasting is an eating plan based on times you allow yourself to consume food,” explains Natalie Allen, R.D., an instructor of biomedical sciences at Missouri State University and the team dietitian for all Missouri State athletes. And it’s pretty strict: “Classically, intermittent fasting means you consume only water during fasting periods, but many variants allow herbal and green tea and coffee, but no sugar or sweeteners,” says Jason Fung, M.D., author of The Complete Guide to Fasting.
But there are a lot of different methods for intermittent fasting, and research is still being done on which one is the most effective. Generally, intermittent fasting refers to periods of fasting that last less than 24 hours but are done more frequently, from daily to weekly. “The most popular regimen is 16:8, a 16-hour fast, which means you have an eight-hour eating window—say, 11 a.m. to 7 p.m—and you can do it most days of the week,” says Fung.
“Another popular regimen is to fast just under 24 hours, say from dinner to dinner, so this is sometimes called one meal a day (OMAD). This would be done two or three times per week, but some do it daily.” And then there’s the Fast or 5:2 method, where you eat normally for five days of the week and cut your calories to 25 percent of your normal intake on two nonconsecutive days of the week.
What About Intermittent Fasting for Weight Loss?
Any sort of intermittent fasting is going to affect the way your body works—and that’s why it’s often used as a weight loss technique. “Basically, you’re consuming less calories, so you lose weight,” says Allen. “If you’re following a 16:8 fasting plan, you would likely consume one big meal a day, skipping breakfast and nighttime eating.”
. Get the Ultimate Guide to Intermittent Fasting amazon.com $24.95
Eating like this can actually help you drop from 3 to 8 percent of your weight over three to 24 weeks, according to a review of studies published in the journal Translational Research; the same study found that people also lost 4 to 7 percent of their waist circumference, which means you can potentially shed the dangerous belly fat that builds up around your middle. Even better, intermittent fasting is less likely to cause muscle loss than continuous calorie restriction, according to research published in the journal Obesity Reviews.
What Are Some Other Results?
On a deeper level, the main effect is on your body’s insulin production. “When you eat, insulin goes up; when you don’t eat (or fast), insulin falls,” explains Fung. “This allows your body to begin to use some of its stored food energy, including glycogen and body fat. And when insulin falls, other hormones increase, including noradrenaline and human growth hormone, which is responsible for the increased energy, well-being, and mental clarity seen with fasting.”
These hormonal changes may increase your metabolic rate by 3.6 to 14 percent, according to research published in the American Journal of Physiology and the American Journal of Clinical Nutrition. “Intermittent fasting can also help with the reversal of type 2 diabetes, prevention of cancer, and Alzheimer’s dementia, and help with anti-aging processes,” says Fung. Studies show, for example, that five consecutive days of fasting can reduce the risk factors for aging and age-related diseases. When you fast, your cells start repair processes including autophagy, which is when cells digest and remove old proteins that build up inside them, according to another study published in the American Journal of Physiology.
What Are the Downsides?
But intermittent fasting only works as well as you stick to the parameters. “Overeating is common,” says Allen. “People know they’re getting ready to fast, so they load up and consume as many calories as they would in a normal day, in just a few hours.” FYI: That completely negates the point of fasting.
Also, limiting your eating to a certain time frame can be tough to sustain. The drop-out rate of people who tried alternate-day fasting was way higher than that of dieters who restricted their calories every day, according to a study published in the journal JAMA Internal Medicine. “Intermittent fasting takes a dedicated person who’s willing to forgo most social eating situations,” says Allen. “It also has a high learning curve, as the carbs need to be low and fat is high, which is opposite of many common meals in the American diet.”
That same study, which lasted a year, found that unhealthy LDL cholesterol had increased significantly after 12 months among the alternate fasting group. “LDL is the ‘bad cholesterol’ associated with heart disease,” says Allen. “We’re concerned about any diet plan that raises LDL.”
Is It Good for Runners?
Just like any other diet plan, intermittent fasting doesn’t work the same for everyone. Pregnant women, children, diabetics, and those with disordered eating tendencies should avoid intermittent fasting, says Allen.
When it comes to elite athletes, “many athletes use ‘training in the fasted state’ to improve performance long-term,” says Fung. Training in a fasted state can allow you to train harder and recover faster, he explains. “This is due to the physiological hormonal changes of fasting. During fasting, noradrenaline (a neurotransmitter involved in your fight or flight response) and sympathetic tone (where muscle tone is maintained predominantly by impulses from the sympathetic nervous system) increase, allowing for more energy and the ability to train harder. Plus, the amount of human growth hormone is increased so recovery is faster.”
That said, there is an adaptation period to fasting, about two to four weeks, when performance may suffer, Fung adds. “When your body isn’t used to fasting, your muscles burn glucose instead of fat. It takes several weeks for them to adapt to fat burning,” he says, during which you may feel sluggish or slow, or even experience stomach issues and diarrhea, adds Allen. It may also affect your mood and motivation.
“People who work out regularly such as runners need carbohydrates for fuel, as carbs are most easily metabolized into energy by the body,” Allen says. “Athletes’ bodies need regular fuel to perform their best. Your blood sugar control, mental clarity (your brain needs glucose), and energy levels can all be negatively affected with intermittent fasting.”
As always, talk to a dietitian or professional about whether it’s right for you if you’re determined to try it while maintaining your run training. At the end of the day, the best diet for you is the one that actually works for your lifestyle, so if intermittent fasting will prevent you from running regularly or feeling strong, then forget the fast, grab a healthy snack, and go crush your next run.
Ashley Mateo Ashley Mateo is a writer, editor, and UESCA-certified running coach who has contributed to Runner’s World, Bicycling, Women’s Health, Health, Shape, Self, and more.
Intermittent Fasting For Women: A Beginner’s Guide
Intermittent fasting not only benefits your waistline but may also lower your risk of developing a number of chronic diseases.
Heart disease is the leading cause of death worldwide (11).
High blood pressure, high LDL cholesterol and high triglyceride concentrations are some of the leading risk factors for the development of heart disease.
One study in 16 obese men and women showed intermittent fasting lowered blood pressure by 6% in just eight weeks (2).
The same study also found that intermittent fasting lowered LDL cholesterol by 25% and triglycerides by 32% (2).
However, the evidence for the link between intermittent fasting and improved LDL cholesterol and triglyceride levels is not consistent.
A study in 40 normal-weight people found that four weeks of intermittent fasting during the Islamic holiday of Ramadan did not result in a reduction in LDL cholesterol or triglycerides (12).
Higher-quality studies with more robust methods are needed before researchers can fully understand the effects of intermittent fasting on heart health.
Intermittent fasting may also effectively help manage and reduce your risk of developing diabetes.
Similar to continuous calorie restriction, intermittent fasting appears to reduce some of the risk factors for diabetes (3, 13, 14).
It does so mainly by lowering insulin levels and reducing insulin resistance (1, 15).
In a randomized controlled study of more than 100 overweight or obese women, six months of intermittent fasting reduced insulin levels by 29% and insulin resistance by 19%. Blood sugar levels remained the same (16).
What’s more, 8–12 weeks of intermittent fasting has been shown to lower insulin levels by 20–31% and blood sugar levels by 3–6% in individuals with pre-diabetes, a condition in which blood sugar levels are elevated but not high enough to diagnose diabetes (3).
However, intermittent fasting may not be as beneficial for women as it is for men in terms of blood sugar.
A small study found that blood sugar control worsened for women after 22 days of alternate-day fasting, while there was no adverse effect on blood sugar for men (6).
Despite this side effect, the reduction in insulin and insulin resistance would still likely reduce the risk of diabetes, particularly for individuals with pre-diabetes.
Intermittent fasting can be a simple and effective way to lose weight when done properly, as regular short-term fasts can help you consume fewer calories and shed pounds.
A number of studies suggest that intermittent fasting is as effective as traditional calorie-restricted diets for short-term weight loss (17, 18).
A 2018 review of studies in overweight adults found intermittent fasting led to an average weight loss of 15 lbs (6.8 kg) over the course of 3–12 months (18).
Another review showed intermittent fasting reduced body weight by 3–8% in overweight or obese adults over a period of 3–24 weeks. The review also found that participants reduced their waist circumference by 3–7% over the same period (3).
It should be noted that the long-term effects of intermittent fasting on weight loss for women remain to be seen.
In the short term, intermittent fasting seems to aid in weight loss. However, the amount you lose will likely depend on the number of calories you consume during non-fasting periods and how long you adhere to the lifestyle.
It May Help You Eat Less
Switching to intermittent fasting may naturally help you eat less.
One study found that young men ate 650 fewer calories per day when their food intake was restricted to a four-hour window (19).
Another study in 24 healthy men and women looked at the effects of a long, 36-hour fast on eating habits. Despite consuming extra calories on the post-fast day, participants dropped their total calorie balance by 1,900 calories, a significant reduction (20).
Other Health Benefits
A number of human and animal studies suggest that intermittent fasting may also yield other health benefits.
- Reduced inflammation: Some studies show that intermittent fasting can reduce key markers of inflammation. Chronic inflammation can lead to weight gain and various health problems (12, 21, 22).
- Improved psychological well-being: One study found that eight weeks of intermittent fasting decreased depression and binge eating behaviors while improving body image in obese adults (4).
- Increased longevity: Intermittent fasting has been shown to extend lifespan in rats and mice by 33–83%. The effects on longevity in humans is yet to be determined (23, 24).
- Preserve muscle mass: Intermittent fasting appears to be more effective at retaining muscle mass compared to continuous calorie restriction. Higher muscle mass helps you burn more calories, even at rest (25, 26).
Specifically, the health benefits of intermittent fasting for women need to be studied more extensively in well-designed human studies before any conclusions can be drawn (27).
Summary Intermittent fasting may help women lose weight and reduce their risk of heart disease and diabetes. However, further human studies are needed to confirm these findings.
There’s a ton of incredibly promising intermittent fasting (IF) research done on fat rats. They lose weight, their blood pressure, cholesterol, and blood sugars improve… but they’re rats. Studies in humans, almost across the board, have shown that IF is safe and incredibly effective, but really no more effective than any other diet. In addition, many people find it difficult to fast.
But a growing body of research suggests that the timing of the fast is key, and can make IF a more realistic, sustainable, and effective approach for weight loss, as well as for diabetes prevention.
The backstory on intermittent fasting
IF as a weight loss approach has been around in various forms for ages, but was highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist Kate Harrison’s book The 5:2 Diet based on her own experience, and subsequently by Dr. Jason Fung’s 2016 bestseller The Obesity Code. IF generated a steady positive buzz as anecdotes of its effectiveness proliferated.
As a lifestyle-leaning research doctor, I needed to understand the science. The Obesity Code seemed the most evidence-based summary resource, and I loved it. Fung successfully combines plenty of research, his clinical experience, and sensible nutrition advice, and also addresses the socioeconomic forces conspiring to make us fat. He is very clear that we should eat more fruits and veggies, fiber, healthy protein, and fats, and avoid sugar, refined grains, processed foods, and for God’s sake, stop snacking. Check, check, check, I agree. The only part that was still questionable in my mind was the intermittent fasting part.
Intermittent fasting can help weight loss
IF makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up as molecules in our bloodstream. Carbohydrates, particularly sugars and refined grains (think white flours and rice), are quickly broken down into sugar, which our cells use for energy. If our cells don’t use it all, we store it in our fat cells as, well, fat. But sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there.
Between meals, as long as we don’t snack, our insulin levels will go down and our fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and for long enough that we burn off our fat.
Intermittent fasting can be hard… but maybe it doesn’t have to be
Initial human studies that compared fasting every other day to eating less every day showed that both worked about equally for weight loss, though people struggled with the fasting days. So, I had written off IF as no better or worse than simply eating less, only far more uncomfortable. My advice was to just stick with the sensible, plant-based, Mediterranean-style diet.
New research is suggesting that not all IF approaches are the same, and some are actually very reasonable, effective, and sustainable, especially when combined with a nutritious plant-based diet. So I’m prepared to take my lumps on this one (and even revise my prior post).
We have evolved to be in sync with the day/night cycle, i.e., a circadian rhythm. Our metabolism has adapted to daytime food, nighttime sleep. Nighttime eating is well associated with a higher risk of obesity, as well as diabetes.
Based on this, researchers from the University of Alabama conducted a study with a small group of obese men with prediabetes. They compared a form of intermittent fasting called “early time-restricted feeding,” where all meals were fit into an early eight-hour period of the day (7 am to 3 pm),or spread out over 12 hours (between 7 am and 7 pm). Both groups maintained their weight (did not gain or lose) but after five weeks, the eight-hours group had dramatically lower insulin levels and significantly improved insulin sensitivity, as well as significantly lower blood pressure. The best part? The eight-hours group also had significantly decreased appetite. They weren’t starving.
Just changing the timing of meals, by eating earlier in the day and extending the overnight fast, significantly benefited metabolism even in people who didn’t lose a single pound.
So, is this as good as it sounds?
I was very curious about this, so I asked the opinion of metabolic expert Dr. Deborah Wexler, Director of the Massachusetts General Hospital Diabetes Center and associate professor at Harvard Medical School. Here is what she told me. “There is evidence to suggest that the circadian rhythm fasting approach, where meals are restricted to an eight to 10-hour period of the daytime, is effective,” she confirmed, though generally she recommends that people “use an eating approach that works for them and is sustainable to them.”
So, here’s the deal. There is some good scientific evidence suggesting that circadian rhythm fasting, when combined with a healthy diet and lifestyle, can be a particularly effective approach to weight loss, especially for people at risk for diabetes. (However, people with advanced diabetes or who are on medications for diabetes, people with a history of eating disorders like anorexia and bulimia, and pregnant or breastfeeding women should not attempt intermittent fasting unless under the close supervision of a physician who can monitor them.)
4 ways to use this information for better health
- Avoid sugars and refined grains. Instead, eat fruits, vegetables, beans, lentils, whole grains, lean proteins, and healthy fats (a sensible, plant-based, Mediterranean-style diet).
- Let your body burn fat between meals. Don’t snack. Be active throughout your day. Build muscle tone.
- Consider a simple form of intermittent fasting. Limit the hours of the day when you eat, and for best effect, make it earlier in the day (between 7 am to 3 pm, or even 10 am to 6 pm, but definitely not in the evening before bed).
- Avoid snacking or eating at nighttime, all the time.
Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial. JAMA Internal Medicine, May 2017.
Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. American Journal of Clinical Nutrition, January 2005.
The Obesity Code, by Jason Fung, MD (Greystone Books, 2016).
Intermittent fasting interventions for treatment of overweight and obesity in adults: a systematic review and meta-analysis. JBI Database of Systematic Reviews and Implementation Reports, February 2018.
Metabolic Effects of Intermittent Fasting. Annual Review of Nutrition, August 2017.
Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism, May 2018.
Should Women Do Intermittent Fasting?
Intermittent fasting is quickly becoming one of the most popular ways to lose weight and improve your health. It’s no wonder: fasting really works well and produces amazing results for a lot of people. The benefits go beyond weight loss, too: fasting can lower inflammation, slow down aging, and give you a stronger brain.
The other nice thing about intermittent fasting is that it’s wonderfully simple: in a nutshell, you just without food for 12-18 hours a day, and then eat all your meals in the remaining hours.
If you’ve been following health and nutrition for a while, though, you may have heard that fasting isn’t great for women. There is some truth there: while some women feel great when they fast, others run into trouble, particularly with their hormones.
The good news is that there are alternatives to traditional fasting! This article will cover the benefits of fasting and the standard approach to fasting, as well as a couple gentler options that you may prefer if you find you don’t do well with full-on daily fasts. Here’s everything you need to know about intermittent fasting for women.
What is intermittent fasting?
Intermittent fasting is wonderfully simple: you don’t eat any calories for 12-18 hours a day (water, coffee, and tea are all fine), and you have a full day’s worth of food in the remaining time.
Here’s an example: let’s say you want to do a 16-hour fast. You could eat all your meals between noon and 8PM (an 8-hour eating window), and not eat anything outside that time (a 16-hour fasting window). In other words, you skip breakfast.
That’s really all there is to traditional intermittent fasting. You can try different fasting times to see what works best for you; the benefits start around a 12-hour fast, and most people don’t go higher than 18 hours.
You might get a little hangry for the first few days fasting, but a lot of people feel amazing after their bodies adjust to fasting. No wonder: fasting can bring you all kinds of benefits.
Intermittent fasting benefits
People have been fasting for thousands of years, and recent scientific research has shed light on what our ancestors seemed to intuitively understand. Fasting is amazing for your body and mind:
- Mental clarity. Fasting gets rid of brain fog by improving your ability to focus and improving your memory . It also increases brain-derived neurotrophic factor (BDNF), a protein that protects your brain from stress and slows down brain aging . Speaking of aging…
- Anti-aging. Fasting turns on autophagy, which is like spring cleaning for your cells. Autophagy is greek for “self-eating,” which is accurate: your system gets rid of old or damaged cells and replaces them with shiny new ones. Fasting causes, to quote one study, “profound autophagy” in your brain , as well as the rest of your body . Autophagy makes your cells younger and more capable, which slows down aging.
- Fat loss. Intermittent fasting makes your metabolism more efficient at burning body fat for energy. People who did intermittent fasting lost more fat than people who did a continuous low-calorie diet .
- Inflammation and immunity. People who did intermittent fasting for Ramadan had a significant decrease in inflammatory markers . Their immune function improved, too.
Basically, your body becomes more efficient and adaptable when you fast.
Should women do intermittent fasting?
Fasting is great if you tolerate it, but some people — especially women — have trouble with hormonal imbalance when they do daily intermittent fasting. Fasting every day causes some women to lose their periods and may interfere with thyroid hormone production, which can be especially hard if you have autoimmune issues.
For those reasons, you may want to try a gentler version of intermittent fasting. Instead of a rigorous daily fast, choose two or three non consecutive days a week (Monday, Wednesday, and Friday, for example) and try a shorter fast on those days; between 12-14 hours is a good place to start. You’ll still get many of the benefits of fasting, but your hormones won’t take the shock that can come from daily fasting. And if you feel good doing shorter fasts a few times a week, you can always increase the length or add a couple more fasting days and see how you feel.
Fasting can be great for women, and you may find you thrive on it. You can always start slowly, with shorter and gentler fasts a couple times a week, and see how your body responds. You may discover that fasting doesn’t work for you at all, and that’s okay too! Find a rhythm that makes you feel good. That’s what’s most important.
What Fit Women Need to Know About Intermittent Fasting
Photo: Joshua Resnick /
Hi, my name is Mallory and I’m addicted to snacking. It’s not a clinically diagnosed addiction, but I know the first step in addressing a problem is recognizing it, so here I am. I reach for food probably every two hours, whether I’m actually hungry or just feel like eating out of boredom or hope it’ll give me a blast of energy. And, the truth is, I just don’t need that much food-especially not late at night when I’m writing (the time of day when my call to munch roars the loudest) and using food to assist in my procrastination.
When I came across the intermittent fasting (IF) meal plan by Autumn Bates, C.C.N., C.P.T., nutritionist and former fitness editor for Tone It Up, my first thought was: Boom. This could be a solution to my snacking habit.
Like many intermittent fasting plans, the most important part of the program is choosing an eight-hour window in which you’ll eat all your meals. (Here’s a breakdown of what intermittent fasting is and why it can be beneficial.) Because I get up around 6 a.m. every day, I chose to have my first meal at 10:30 a.m. and my last one at around 6 p.m. so I’d be done eating for the day by 6:30. While lots of people try intermittent fasting for weight loss results, I thought this locked-in eating period—plus following the plan to eat three meals a day, with just one snack—could cure my late-night noshing.
Spoiler alert: It kind of did. If you’re curious about my personal intermittent before and after lessons, read on for my intermittent fasting results from the 21-day IF plan.
1. Post-dinner snacks aren’t necessary if I have a hearty meal.
This was proof of what I already knew to be true but chose to ignore: When you have a satisfying dinner (Bates often recommended a lean meat and some starchy vegetables) you really don’t have to reach for popcorn or almonds or even carrots before going to bed. And that’s especially true when you’re hitting the sheets on the early side. (See: How Bad Is It to Eat At Night, Really?)
My nighttime routine often included going to the kitchen to grab a bite before sitting down to write or watch TV. With the fasting schedule, this was obviously off-limits. Instead, I’d fill up a glass of water and drink while I worked. Not only did I realize how good I still felt sans the added calories, but I was mentally proud of myself for getting in even more H2O-a feat I don’t always find easy. Which leads me to…
2. Starting the day with water really is smart.
I’ve previously tried to throw back a bottle of agua before drinking coffee, and I’ve stuck with it for a day or two. But then I’m right back to Starbucks before the thought of water even crosses my headspace. While Bates’ plan called for having at least an eight-ounce glass immediately after getting up in the morning, I’d often finish a whole 32-ounce bottle before having some food. (Here’s what happened when one writer drank twice as much water as usual.)
What’s more: While following the diet, I really tried to zero in on whether I actually felt hungry before I ate. Drinking water before reaching for food was one major thing that helped me better recognize my hunger levels. It’s a habit that’s stuck with me since finishing the plan, and one I actually aim to maintain. After all, experts do say we tend to mistake thirst for hunger. So when you’re fully hydrated and still ready for food, then you know it’s time to take a bite.
3. Having healthy fats at breakfast kept me full through lunch.
I loved the almond smoothie from Bates’ plan, which I cut down to just a few ingredients: almond milk, almond butter, flaxseed meal, cinnamon, a frozen banana, and a scoop of plant-based protein powder (with an occasional tablespoon of chia seeds). I’d often make this the night before, throw it in the freezer to take with me in the morning, and then eat it with a spoon come breakfast. I looked forward to that first spoonful every single day. The best part was that I truly felt full for the next few hours. I think this was one of my best intermittent fasting results: a fulfilling breakfast in portable-smoothie-form that I actually craved. (Try this almond butter superfood smoothie for yourself.)
4. With more time to digest, I definitely felt less bloated.
One of the intermittent fasting results Bates mentions in her program is better gut health. She suggests having an “ACV sipper” 20 minutes before your first meal-that’s a tablespoon of apple cider vinegar in 8 ounces of water. I didn’t do this every day, but thanks to my wholehearted love for ACV (and all its benefits), I enjoyed the days I did. The ACV is meant to help you digest your first meal better. (Just a heads up, though: ACV may be ruining your teeth.)
I can’t be sure this is what kept me from getting bloated by the afternoon (something I deal with on the reg), but I really did feel “deflated” on this plan. The full 16 hours of fasting at night probably didn’t hurt either, along with more time to digest between meals. (The perks of snack-free life are really starting to add up!).
5. It might not be right for the morning exerciser.
My biggest setback on this diet: morning workouts sans food. Four or five days a week, I take HIIT or strength classes around 8 a.m. or try to go for a run. Without a little fuel to get me to the finish, I found myself feeling weak and resorted to dialing down most exercises instead of busting my butt.
Because I’m pretty active, Bates had suggested I do crescendo fasting-meaning I should follow the same meal plan, but only stick to the 16-hour fasting window on non-consecutive days. (That way, I could have breakfast a little earlier on the mornings I work out, and extend my eating window past the aforementioned eight hours.) I chose to ignore that recommendation in favor of trying the full-out plan, and it wasn’t my best idea.
I spoke to another sports-specific dietitian, Torey Armul, M.S., R.D., a spokesperson for the Academy of Nutrition and Dietetics, about whether an IF plan is a good idea for the super active. Her short answer: No. “Your muscles need fuel to function properly, and carbohydrates are the most efficient source of muscle fuel. Your body can store carbohydrates, but only for a few hours at a time. That’s why you’re hungry when you wake up in the morning, and why you ‘hit the wall’ during morning workouts if you haven’t eaten yet,” Armul explains. (For example: Here’s what you should be eating after a HIIT workout.) “One of the worst things you could do is to continue fasting after a tough workout, since recovery nutrition is vitally important. That’s why intermittent fasting and intense exercise/training for an event just aren’t a good match.”
So, there you have it: While intermittent fasting gave me the results I wanted (to cut back on snacking) and I would totally do it again, I’ll probably skip the fasting schedule any time I’m vying for a finisher’s medal.
- By Mallory Creveling
A guide to 16:8 intermittent fasting
Researchers have been studying intermittent fasting for decades.
Study findings are sometimes contradictory and inconclusive. However, the research on intermittent fasting, including 16:8 fasting, indicates that it may provide the following benefits:
Weight loss and fat loss
Eating during a set period can help people reduce the number of calories that they consume. It may also help boost metabolism.
A 2017 study suggests that intermittent fasting leads to greater weight loss and fat loss in men with obesity than regular calorie restriction.
Research from 2016 reports that men who followed a 16:8 approach for 8 weeks while resistance training showed a decrease in fat mass. The participants maintained their muscle mass throughout.
In contrast, a 2017 study found very little difference in weight loss between participants who practiced intermittent fasting — in the form of alternate-day fasting rather than 16:8 fasting — and those who reduced their overall calorie intake. The dropout rate was also high among those in the intermittent fasting group.
Supporters of intermittent fasting suggest that it can prevent several conditions and diseases, including:
- type 2 diabetes
- heart conditions
- some cancers
- neurodegenerative diseases
However, the research in this area remains limited.
A 2014 review reports that intermittent fasting shows promise as an alternative to traditional calorie restriction for type 2 diabetes risk reduction and weight loss in people who have overweight or obesity.
The researchers caution, however, that more research is necessary before they can reach reliable conclusions.
A 2018 study indicates that in addition to weight loss, an 8-hour eating window may help reduce blood pressure in adults with obesity.
Other studies report that intermittent fasting reduces fasting glucose by 3–6% in those with prediabetes, although it has no effect on healthy individuals. It may also decrease fasting insulin by 11–57% after 3 to 24 weeks of intermittent fasting.
Time-restricted fasting, such as the 16:8 method, may also protect learning and memory and slow down diseases that affect the brain.
A 2017 annual review notes that animal research has indicated that this form of fasting reduces the risk of nonalcoholic fatty liver disease and cancer.
Extended life span
Animal studies suggest that intermittent fasting may help animals live longer. For example, one study found that short-term repeated fasting increased the life span of female mice.
The National Institute on Aging point out that, even after decades of research, scientists still cannot explain why fasting may lengthen life span. As a result, they cannot confirm the long-term safety of this practice.
Human studies in the area are limited, and the potential benefits of intermittent fasting for human longevity are not yet known.
5 Reasons You Haven’t Seen Intermittent Fasting Results, According to Nutritionists
Over a third of U.S. consumers are currently dieting—and the majority of them are following intermittent fasting or IF. If you haven’t yet been acquainted with the trend, IF is an eating pattern that involves abstaining from food for a specific period of time (usually overnight) and limiting meals to an eating window. Many people are interested in the diet because they can see intermittent fasting results in as little as 10 days.
What are the benefits of intermittent fasting?
Besides being linked to boosting your metabolism, “Research seems to be finding benefits to weight, blood sugar, inflammation, and potentially to brain health,” Isabel Smith, MS, RD, CDN, and founder of Isabel Smith Nutrition and Lifestyle, tells us.
Why haven’t you seen intermittent fasting results while following the diet?
However, while research shows that many folks are trying their luck with IF, people often find that they’re not seeing optimal intermittent fasting results as quickly as they expected.
If you’re not witnessing a trimmer waistline and bloat-free belly, don’t quit just yet—you may be guilty of committing these five mistakes.
Find out how you can improve your IF experience and reap the results you’ve been dreaming of before throwing in the towel with our guide below.
Stop the following 5 bad habits so you can finally see the intermittent fasting results everyone raves about.
You chose the wrong eating window.
There are multiple IF plans, and there’s no one-size-fits-all.
- 5:2 approach: This plan involves eating your normal diet five days out of the week and restricting your caloric intake to 500–600 calories for the remaining two.
- 8:16 approach: During the 8:16 approach, your eating window is 8 hours long during the day, and the 16-hour fasting period occurs overnight.
- Warrior Diet: This approach involves eating small amounts of produce during the day and indulging in a big meal at night.
- Eat-Stop-Eat plan: This is the method that involves one or two 24-hour fasts per week.
Because there are so many options, you may not be seeing intermittent fasting results if you’re following the wrong IF plan for your lifestyle.
For example, if your weekdays involve hitting the gym for an a.m. sweat sesh, working overtime, and then rushing to get dinner on the table, the 5:2 eating plan may be too restrictive and leave you feeling famished—a recipe for IF failure.
“Some may find that a 12-hour fasting window is all they can do without major discomfort, while others do just fine with a 16-hour fast. For beginners, start with 12 hours and build up from there,” Jim White, RDN, ACSM, EX-P, owner of Jim White Fitness and Nutrition Studios, explains.
You aren’t eating enough calories.
MC Jefferson Agloro/Unsplash
Registered dietitian Amy Shapiro MS, RD, CDN of Real Nutrition NYC reminds us that not eating enough during your eating window and still trying to cut calories can backfire. “People often try to count the calories they eat during the window, however, that is not the point. The goal is to eat until you’re full, which your body will tell you. By restricting calories, you will under-eat, causing unwanted changes in the body, which can be detrimental long-term,” she tells us.
For successful weight loss and intermittent fasting results, White recommends specific calorie restrictions. (He also notes that caloric needs change based on levels of physical activity and age.):
- For women: 1,200–1,800 calories
- For men: 1,800–2,200 calories
“To avoid dipping too low in energy, which could compromise energy and productivity levels during your day, try eating three smalls meals and one to two snacks during your eating window,” White advises. “Additionally, eating only one time a day can lead to extreme levels of hunger which would make it very challenging to make healthful choices at the moment and often lead to overeating.”
You’re eating the wrong foods during your window.
Just because IF focuses on your meal timing rather than macro-tracking, that doesn’t give you the green light to engage in a junk food free-for-all.
“Eating the wrong foods during the eating window and not getting enough nutrients is often a problem while intermittent fasting,” Shapiro tells us. “It is essential to nourish the body with nutrient-dense whole foods so that the body can break them down during the fasted state, keeping you satiated. People use IF as an excuse to eat the wrong things, such as processed foods and sugar, which is not good for the body during the fasted state.”
To see intermittent fasting results, White recommends making the following healthy foods a priority in your diet:
- healthy fats
- lean proteins
- complex carbohydrates
- fiber found in fruits and vegetables
You’re forgetting to drink water throughout your intermittent fasting diet.
Fasting or not, staying hydrated helps you fight off hunger and cravings. Shapiro reminds us how essential it is to drink up during the fasted state. “Since the body is breaking down components while you fast, water is needed to detoxify them and flush out the toxins. This can also help you to feel full,” she says.
Try keeping a large reusable water bottle by your desk so you can sip throughout the day.
You’re overtraining during the diet.
If you’re planning to hit the gym during your IF period, make sure not to overdo the HIIT circuits or else you may not see the intermittent fasting results you were expecting.
Of course, your workout schedule will depend on which IF diet you’re following:
- 8:16: If you’re following 8:16 and skip your usual breakfast, engaging in a morning workout on an empty stomach will leave you feeling extremely low on energy and could impact your workout performance and speed of muscle recovery, White says.
- 5:2: Similarly, working out during the calorie-restricted days on 5:2 won’t help you get the most out of your workout and leave you feeling ravenous. “The body has to be eased into the process of IF. The process works if you do it correctly, but eating too little and training too hard can lead to adrenal fatigue.
Working out is great, but too much stress on the body will be a problem,” Shapiro tells us. Planning to take a stab at this trend? You’ll want to see what happens when someone tries intermittent fasting for 10 days.
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Earlier this week, I posted a brief guide on getting started with intermittent fasting. You can read it here.
Intermittent fasting is a great tool for getting strong and lean without changing your diet. But it can also seem confusing or extreme if you’re not familiar with it. In fact, my guide seemed to prompt quite a few questions, many of which I responded to over email.
Because you may be wondering many of the same things, I figured I should write about them here as well as share some of the important lessons I’ve learned from practicing intermittent fasting for over one year.
Free Bonus: I created an Intermittent Fasting Quick Start Guide with a summary of the benefits of intermittent fasting and 3 fasting schedules you can use depending on your goals. It’s a quick 5 page PDF you can save and reference later as you try this yourself. .
12 Lessons Learned from 1 Year of Intermittent Fasting
1. The biggest barrier is your own mind.
Implementing this diet is pretty simple, you just don’t eat when you wake up. Then you eat and lunch and go about your day. At least, that’s how I do it.
But there is a mental barrier to get over. “If I don’t eat will I not be able to think? Will I faint? Will I feel sick? What will it be like?” These are all thoughts that went through my mind before I started.
What ended up happening? Nothing. Life went on just fine.
Thinking you need to eat every 3 hours or six meals a day or always have breakfast or whatever it is that you’re convinced you have to do to survive … is all mental. You believe it because you were told it, not because you actually tried it.
If there’s one thing I’ve noticed that separates successful people from unsuccessful ones in life it’s not just the ability to think differently, but the ability to act differently as well.
2. Losing weight is easy.
When you eat less frequently you tend to eat less overall. As a result, most people who try intermittent fasting end up cutting weight. You might plan big meals, but consistently eating them is difficult in practice.
For this reason, I think intermittent fasting is a great option for people who are looking to lose weight because it offers a simple way to cut down on the total number of calories you eat without changing your diet. Even if you tell people that they can eat two large meals at lunch and dinner, they typically end up eating fewer calories than they would at 3 or 4 normal meals.
Most people lose weight while intermittent fasting because when they cut out meals, they don’t make up for it with bigger meal sizes.
3. Building muscle is quite possible (if that’s what you want).
I have managed to gain weight while intermittent fasting (I’ve added about 12 pounds of lean body mass and cut 5 pounds of fat over the last year), but only because I have focused on eating a lot during my feeding period.
As I mentioned above, the natural tendency is to lose weight on intermittent fasting because it’s easy to eat less when you cut a meal out of your day. However, at the end of the day eating 2,000 calories is eating 2,000 calories whether it comes during a 16–hour span or an 8–hour span. It just takes more effort to make sure you eat it all within 8 hours.
It’s totally reasonable to build muscle as long as you eat enough.
4. My best work is usually done when I’m deep into my fast.
I’m most productive during the first 3 hours of my morning, which is about 12 to 15 hours into my daily fast. This is the exact opposite of what I expected when I started out. I assumed that if I didn’t eat for hours, then I wouldn’t have any energy to think. The reality is just the opposite.
I have a lot of mental clarity in the morning when I fast. I can’t say for certain if this is due to the fasting or the fact that I’m just refreshed when I wake up, but one thing is clear: fasting is not hindering my ability to get things done in the morning. In fact, I’m almost always more productive in the morning when I’m fasted than in the afternoon when I’m fed.
5. For best results, cycle what you eat.
Intermittent fasting works, but I didn’t start cutting fat at a significant rate until I added in calorie cycling and carb cycling to my diet. Here’s how it works…
I cycle calories by eating a lot on the days that I workout and less on the days that I rest. This means I have a calorie surplus on the days I train and a calorie deficit on the days that I rest. The idea behind this is that you can build muscle on the days you train and burn fat on the days you rest. And by the end of the week, you should have done both.
Additionally, I cycle carbs by eating a lot of carbohydrates on the days that I train and few carbohydrates on the days that I rest. This is done to stimulate fat loss. I eat high protein all the time and moderate to low fat on most days. Cycling carbohydrates has also led to additional fat loss.
For me, this is when the intermittent fasting seemed to pay off the most — when I coupled it with calorie cycling and carb cycling.
6. Like most things, you should take a long–term view of eating.
Too often we think about our diet in super short timeframes.
It’s better to think about what we eat over the course of a week than over the course of a day (or worse, a few hours). For example, whether or not you have a protein shake within 30 minutes of working out, is largely a non–issue if you’re getting a meal of quality protein within 24 hours of working out.
One reason intermittent fasting works is because the super short timeframes that we are pitched by food companies and supplement companies are largely a myth. Let’s say you eat 3 quality meals per day. That’s 21 meals per week. Over the course of a week, do you think your body cares if the meals are eaten from 8am to 8pm (the normal eating schedule) or 1pm to 8pm (an intermittent fasting schedule)?
How about if we stretch it out over the course of a month? Wouldn’t it make sense that if you ate 80 quality meals every month (about 3 per day) that your body would make the most of those meals whether you ate them in an 8–hour block or a 12–hour block on each individual day?
When you take a slightly longer view, you start to realize that the time difference between eating from 8am to 8pm versus eating from 1pm to 8pm isn’t that large over the course of a week or a month.
7. It’s strange, but when I’m fasting I want food less.
Now that I’ve started fasting, I want food less. I’m not addicted to it. I’m not a victim to my diet. I eat when I want because I want to, not because my body tells me I have to.
This is a marked change from my previous eating schedule and I think the additional power and flexibility I have over my diet now is a benefit.
8. Losing fat and gaining muscle can both be done, just not together.
If you’re looking to lose fat and build muscle mass, then the combination of intermittent fasting, calorie cycling, and carb cycling that I have mentioned here is one of the best solutions you’ll find.
You see, it’s basically impossible to gain muscle and lose fat at the same time. To lose weight, you need to burn more calories than you take in. You need to have a net calorie deficit.
To build muscle, you need to eat more calories than you burn. You need to have a net calorie surplus.
It should be fairly obvious that you can’t have a net surplus and a net deficit at the same time. For example, you can either eat more than 2,000 calories or you can eat less than 2,000 calories … but you can’t do both at the same time. This is why it’s basically impossible to lose fat and gain muscle at the same time.
However, if we get away from the small timeframes and start thinking about our diet over the course of a week or a month, then we start to have more options. For example, let’s say that you workout 3 days per week. You could organize your eating routine to have a calorie surplus on the days you train (i.e. gain muscle) and then a calorie deficit on the days you rest (i.e. lose fat). That way, by the end of the week, it’s possible for you to have spent 3 days gaining muscle and 4 days losing fat.
9. When fasting, I have made more gains by training less.
I’ve recently began testing a new hypothesis for strength training, which I call “Do The Most Important Thing First.”
It’s as simple as it sounds. I pick one goal for the workout and do the most important exercise first. Everything else is secondary. For example, right now I’m working out Monday, Wednesday, and Friday. I do two sessions each day. Upper body in the morning. Lower body in the evening. But I’m only doing one exercise each time (pushups in the morning) and squat or deadlift in the evening. If I feel like it, I’ll finish my evening workout with kettlebell work or bodyweight stuff (handstands, front levers, and so on).
The results have been very good. I’ve seen improvement each and every week over the last three months. It’s worked so well that I’m starting to think that it has very little to do with fasting, but instead is just a better way of training. I’ll write more about this in the future, but I wanted to note it here because when I compare it to the previous way I trained while fasting (snatch and clean and jerk three days per week, plus squat or deadlift), I seem to be making more progress.
10. As long as you stay under 50 calories, you’ll remain in the fasted state.
A lot of people like to start their day with a cup of coffee or a glass of orange juice. Maybe you’re one of them. I have a glass of water. Well you don’t have to dump your morning routine if you want to give fasting a try.
The general rule of thumb is that if you stay under 50 calories, then you’ll remain in the fasted state. I’m not sure where this number came from, but I’ve seen it dished around by enough reputable people that I’m going to go with it for now. Following the opinion of the majority is typically a lazy move, but in this case I think you’ll be alright if you want to have a cup of coffee in the morning.
11. Prepare to drink a lot of water.
I drank a lot of water before I began intermittent fasting, but now I drink an incredible amount. I’m usually over 8 glasses for the day by the time I get done with lunch.
You mileage may vary, but even if you don’t drink as much water as I do, I recommend having it at the ready.
12. The best diet for you is the one that works for you.
Everyone wants to be handed the ultimate diet plan. We all want the answers on one sheet of paper. “Here. Just do this and you’ll be set.”
This is why diet books sell so well. A lot of people are willing to pay for a quick fix, a diet in a box, or the nutritional solution to long life.
Here’s my problem with marketers telling everyone that their diet is the best: it’s like telling the whole world to wear medium sized shirts and then wondering why they don’t fit a lot of people.
In most ways, your body is the same as everyone else’s. But in some very important ways, it’s also different than everyone else’s. To find the diet that works best for you, you need to experiment and see what your body responds to.
This is why I enjoy intermittent fasting. You can play with your eating schedule very easily. Choose one that fits your lifestyle and that your body responds to. Once you figure out when you should be eating, then you can move on to the harder part: what you should be eating.
As always, your mileage will vary, but the most important thing is that you’re covering ground and moving forward.
Free Bonus: I created an Intermittent Fasting Quick Start Guide with a summary of the benefits of intermittent fasting and 3 fasting schedules you can use depending on your goals. It’s a quick 5 page PDF you can save and reference later as you try this yourself. .
Kathleen’s 21 Day Water Fast Journey @TheLifeCoPhuket
Kathleen is here enjoying her second The LifeCo detox experience with us in Phuket; we are very excited to have her back so soon! Her first time at The LifeCo Bodrum was February 2018, and she had such a great experience on the Green Juice program that she decided to fly all the way to Thailand to join us again, but this time she really pushed the boundaries and decided to do a water fast! The good news is she is going to share the experience with us all…
So here we are sitting down looking at the beautiful lake in the middle of the centre surrounded by luscious green jungle like trees and bright blue sky with not a cloud in sight!
Name – Kathleen Jones
Age – 53
From – California
Profession – Producer (Entertainment)
What was your main motivation to water fast for 21 days?
As I am a cancer “thriver” I wanted to really clean out my body and train my cells to continue being my wonderful cellular police force against any invaders or unnecessary things in my body. I also wanted to reboot my mind for 21 days to understand the importance of water fasting so I can make it a part of my weekly and yearly health maintenance.
What were your desired results?
To totally reboot my cellular cleaning system and get to know my “cells” again. I spoke with them every day, build a new relationship with my little army inside keeping me healthy.
How were your first 72 hours? What was the hardest part of the fasting?
The first 3 days were the most difficult but after 3 days, I knew in the back of my mind I would do 21 days but I didn’t put pressure, my next jump was 7 days, after that it was easy to get to 10 days, then 14 days…. at 14 days my energy was a little low, but didn’t stop me from exercising every day and working full time. The decision to jump from 14 days to 21 days took a bit of meditation, but I knew in my heart 21 was the number for me, so I went for it.
How were your energy levels, mood, emotional and mental state..?
Energy level was great throughout… after saunas it went down a little bit, but in general I felt really positive and good. Mental state was amazing throughout.
What did you crave the most?
I craved the food at The LifeCo 🙂 Probably because I saw it each day…everything they server here just looked amazingly healthy and tasty. I didn’t crave any crap food at all.
How did you cope with your hunger?
I didn’t feel hungry… it was very odd. Only on the last 3 days did my tummy start to grumble a little bit…
How was your sleep quality?
Better than usual but I do have sleep issues in general. I was dreaming a lot and sleeping enough..
What activities did you participate daily?
I did a few classes a day and saunas, and of course worked full time. I went to the beach every morning and walked from 7:45 – 9:30 and then swam from 9:30 – 10:30… sometimes I went back to the beach and walked another 1.5 hours in the evening.
Did you do colon therapies?
Just Angel of Water (colema) most days and two colon hyrdo therapy sessions per week.
Which therapies helped you the most?
Tenzin’s classes, love Dr. Lodi, love the saunas.
How much weight you have lost?
I haven’t weighed myself in 30 years, no idea, I’m guessing 15 – 20 pounds.
How did you feel when you were breaking your fast?
Good, it’s day three and I feel back to normal energy… First 2 days were a little slower, but I feel back.
Water Fasting: Benefits and Dangers
Both human and animal studies have linked water fasting to a variety of health benefits.
Here are a few health benefits of water fasting.
May promote autophagy
Autophagy is a process in which old parts of your cells are broken down and recycled (4).
Several animal studies suggest that autophagy may help protect against diseases like cancer, Alzheimer’s, and heart disease (9, 10, 11).
For example, autophagy may prevent damaged parts of your cells from accumulating, which is a risk factor for many cancers. This may help prevent cancer cells from growing (12).
Animal studies have consistently found that water fasting helps promote autophagy. Animal studies also show that autophagy may help extend life span (1, 3, 13).
That said, there are very few human studies on water fasting, autophagy, and disease prevention. More research is needed before recommending it to promote autophagy.
May help lower blood pressure
Research shows that longer, medically supervised water fasts may help people with high blood pressure lower their blood pressure (14, 15).
In one study, 68 people who had borderline high blood pressure water fasted for nearly 14 days under medical supervision.
At the end of the fast, 82% of people saw their blood pressure fall to healthy levels (120/80 mmHg or less). Additionally, the average drop in blood pressure was 20 mmHg for systolic (the upper value) and 7 mmHg for diastolic (the lower value), which is significant (14).
In another study, 174 people with high blood pressure water fasted for an average of 10–11 days.
At the end of the fast, 90% of people achieved a blood pressure lower than 140/90 mmHg — the limits used to diagnose high blood pressure. Additionally, the average fall in systolic blood pressure (the upper value) was a substantial 37 mmHG (15).
Unfortunately, no human studies have investigated the link between short-term water fasts (24–72 hours) and blood pressure.
May improve insulin and leptin sensitivity
Insulin and leptin are important hormones that affect the body’s metabolism. Insulin helps the body store nutrients from the bloodstream, while leptin helps the body feel full (16, 17).
Research shows that water fasting could make your body more sensitive to leptin and insulin. Greater sensitivity makes these hormones more effective (18, 19, 20, 21).
For example, being more insulin sensitive means your body is more efficient at reducing its blood sugar levels. Meanwhile, being more leptin sensitive could help your body process hunger signals more efficiently, and in turn, lower your risk of obesity (22, 23).
May lower the risk of several chronic diseases
There is some evidence that water fasting may lower the risk of chronic diseases like diabetes, cancer, and heart disease (2, 24, 25).
In one study, 30 healthy adults followed a water fast for 24 hours. After the fast, they had significantly lower blood levels of cholesterol and triglycerides — two risk factors for heart disease (26).
Several animal studies have also found that water fasting may protect the heart against damage from free radicals (2, 27).
Free radicals are unstable molecules that can damage parts of cells. They are known to play a role in many chronic diseases (28).
Moreover, animal research has found that water fasting may suppress genes that help cancer cells grow. It may also improve the effects of chemotherapy (29).
Keep in mind, only a handful of studies have analyzed the effects of water fasting in humans. More research in humans is needed before making recommendations.
Summary Research shows that water fasting may lower the risk of many chronic diseases and promote autophagy. However, most research is from animal or short-term studies. More studies are needed before recommending it.