Does ‘Calories in vs. Calories out’ Really Matter?

While the “calories in versus calories out” model matters for weight loss, not all calories are created equal when it comes to your health.

That’s because different foods have different effects on various processes in your body, regardless of calorie contents.

The source of calories impacts your hormones and health differently

Different foods can affect your hormone levels in different ways.

The differing effects of glucose and fructose serve as a good example. These two simple sugars provide the same number of calories per gram, but your body metabolizes them in completely different ways (18).

A diet too rich in added fructose is linked to insulin resistance, increased blood sugar levels, and higher triglyceride and LDL (bad) cholesterol levels than a diet providing the same number of calories from glucose (19).

That said, fruit, which contains natural fructose along with fiber and water, does not have the same negative effects.

What’s more, the type of fat present in your diet can have different effects on your reproductive hormone levels. For instance, diets rich in polyunsaturated fats appear to boost fertility in healthy women (20).

What’s more, replacing saturated fats with unsaturated fats in your diet may further lower your risk of heart disease, even though both types provide the same number of calories per gram (21).

The types of food you eat affect how full you feel

Your nutrient intake impacts your hunger and feelings of fullness.

For instance, eating a 100-calorie serving of beans will reduce your hunger much more effectively than eating a 100-calorie serving of candy.

That’s because foods rich in protein or fiber are more filling than foods containing lower amounts of these nutrients (22, 23, 24).

The candy, which is low in fiber and protein, is much more likely to lead you to overeat later in the day, reducing the likelihood that your “calories in” will match your “calories out.”

Similarly, fructose tends to increase levels of the hunger hormone ghrelin more than glucose does.

It also doesn’t stimulate the fullness centers in your brain in the same way as glucose, so you won’t feel as full after eating fructose as you would after eating glucose (25, 26).

This is why most processed foods that are rich in fructose but devoid of protein or fiber generally make it more difficult for you to maintain an energy balance.

The source of calories has different effects on your metabolism

Foods affect your metabolism differently. For instance, some require more work to digest, absorb, or metabolize than others. The measure used to quantify this work is called the thermic effect of food (TEF).

The higher the TEF, the more energy a food requires to be metabolized. Protein has the highest TEF, while fat has the lowest. This means that a high-protein diet requires more calories to be metabolized than a lower-protein diet does (2, 3).

This is why eating protein is often said to boost your metabolism to a greater extent than eating carbs or fat. That said, when it comes to weight loss, the TEF of foods appears to have only a small effect on your calorie balance (27, 28, 29).

Summary Different foods can impact your hormones, hunger, feelings of fullness, and metabolism differently, regardless of the number of calories they contain. Thus, when it comes to your health, not all calories are created equal.

Calories In, Calories Out

When it comes to weight loss, no formula is more maligned or misunderstood than the calories in, calories out equation. Attempts to either defend or refute this equation in a public forum invariably result in heated debate, even among circles of people with advanced nutrition, biology, or even physics degrees .

On the surface, the calories in, calories out debate is difficult to understand. This equation is derived from the first law of thermodynamics, reading that “energy cannot be created or destroyed in an isolated system.” Across decades of increasingly precise scientific measurements of energy systems, no exceptions to this first law have been found.

Further, because the human body is a type of energy system, it follows that biological processes such as weight loss must also operate in accordance with this law. In reference to the calories in, calories out equation, this means that a human body can neither gain energy (i.e., gain weight, because energy also has mass) without a source to obtain the energy (e.g., increasing calories in by eating more) nor lose energy (i.e., lose weight) without a process that allows energy inside us to leave the body (e.g., increasing calories out by moving more; see Ruben Meerman’s TEDxQUT talk on YouTube for an excellent visual explanation of the chemical process of weight loss ).

Combine the calories in, calories out equation with estimates of the amount of energy stored in fat (about 3,500 kcal in a pound of body fat), and this becomes the source of common advice about losing a pound of weight a week by reducing calories in by 500/day, increasing calories out by 500/day, or achieving the same total through a combination of diet and exercise. Simple!

The problem is that when people apply the calories in, calories out formula to their weight loss experiences, their results rarely align with what is predicted. For example, many go on diets only to find that they lose less weight than their calories in, calories out equation suggests. Others exercise more, only to find that their increased calories out total exceeds the weight loss they achieve. And these are only the most common examples.

Observations of different weight loss results from different diets, weight gain side effects of medicines, hormone changes—such as those resulting from menopause and thyroid dysfunction—and even controlled studies where people gain or lose different amounts of weight despite being feed carefully measured portions, all seem to counter the calories in, calories out equation. When real-world weight loss results routinely fail to meet the formula’s predictions, the debate about the calories in, calories out equation begins to make sense.

The static version of the equation Source: Thomas Rutledge

It turns out that both sides of the calories in, calories out debate are correct in their own ways. Critics of the calories in, calories out equation, for example, rightly argue that simply eating less and moving more will not reliably predict weight loss when the formula is used in a static form. For instance, if a person only compares their calories consumed to their calories expended through exercise, their weight loss prediction may be very different from their results measured on a scale.

And, unfortunately, most people use the calories in, calories out formula only in a simple and static form for reasons that are predictable. Our minds crave simplicity, including for weight loss, seducing us into believing that there is a special diet, exercise, or supplement that has all the answers, even when the reality is more complex.

This is where the advocates of the calories in, calories out equation are correct: When the formula is used in a dynamic way, it accurately accounts for every weight loss result, including all the so-called exceptions that people think prove the formula wrong. The figure below shows an example of a simple-static application of the calories in, calories out equation versus a dynamic application of the same equation.

The dynamic version of the equation Source: Thomas Rutledge

To expand from the figure in a practical way, consider how the dynamic application of the calories in, calories out equation explains each of the following results thought to disprove the equation.

1. If the calories in, calories out equation is true, then why do people lose more weight with keto or low-carb diets?

Perhaps the most common objection to the equation is the markedly different short-term weight loss results people observe when following low-carb diets. Even a smaller person may lose five pounds in the first week on a keto diet, for example, and a larger person may lose 10 or more pounds.

Compare this to a one- to two-pound weight loss by a person on a normal carbohydrate diet—with the same calories—and the calories in, calories out equation seems fatally flawed. However, this is also the most easily explained result; the rapid weight loss achieved by low-carb diets is the result of water loss rather than a loss of body fat. Fat loss does not differ between calorie-matched lower and normal carbohydrate diets, as shown in many clinical trials.

2. If the calories in, calories out equation is true, then why can some people “eat whatever they want” and never gain weight, while others must watch every calorie?

Even in two people of the same size and gender, following the same diet and exercise routines, weight loss results can still differ in important ways explained by the calories in, calories out equation.

For instance, the kind of physical activity scientists call NEAT—referring to non-exercise movement outside of formal exercise—can differ substantially between people of the same age and size. Some people fidget, pace, stand, and gesture more, whereas others are just the opposite. Further, this source of energy expenditure is dynamic, changing in response to calorie intake.

Ever notice that some people eat a large Thanksgiving dinner and then crash on the couch (lowering NEAT)? Other people do the opposite, becoming more active after overeating. The famous 1999 study from Science finding that overfeeding people resulted in different weight gain results, for instance, was explained by differences in NEAT, entirely consistent with the calories in, calories out equation—even though some try to use the study as a refutation of the equation.

3. If the calories in, calories out equation is true, then why can’t people with poor thyroid function lose weight even when they are eating very few calories?

This is also a common argument against the equation that, in fact, strengthens it. Poor thyroid function decreases the calories out side of the equation in two ways.

First, low thyroid function reduces body temperature. This is critical because body heat is the largest component of our basal metabolic rate. Lowering temperature even by a degree or two results in hundreds of fewer calories used per day. Secondly, low thyroid function results in fatigue, reducing calories out by lowering exercise and general movement. Combine these two effects, and the weight loss difficulties reported by people with poor thyroid function is entirely consistent with the calories in, calories out formula.

4. If the calories in, calories out equation is true, then why do people gain weight as they get older, even when they eat and exercise the same as always?

As people go from youth to older ages—even maintaining the same diet and lifestyle—their calories out usually decrease in ways that promote weight gain. First, most people lose muscle as they age. Muscle is high maintenance material and requires more energy to preserve than body fat. As muscle loss accumulates over time, the metabolic rate declines.

Secondly, general movement (NEAT) also usually decreases with age. Children can be in constant motion, whereas older-aged people move much less in comparison. This adds up, in the average person, to a calories-out total that may be hundreds less per day than among their younger self. As predicted by the calories in, calories out equation, the usual result is gradual weight gain even when calories and exercise are the same.

5. If the calories in, calories out equation is true, then why do people hit weight-loss plateaus even when they keep up their diet and exercise programs?

Plateaus are a great example of the dynamic nature of the body’s energy balance system. As a person loses weight, their calories out decrease even when they maintain the same diet and exercise routines. This is because, with a smaller body, their basal metabolic rate decreases, as does their energy expended during exercise and general movement.

Consider that a larger person is like a V8 engine in a car. A big engine requires a lot of fuel to function. As that person loses weight, however, they become a V6 engine that needs less and less fuel. Simply put, weight-loss plateaus are further evidence of the need to treat the calories in, calories out equation dynamically rather than statically. Plateaus are a reminder that we need to keep adjusting our weight-loss approach over time to keep getting results.

Source: Thomas Rutledge

Counting Calories is a Ridiculous Way to Try to Lose Weight

Dr. Jason FungFollow May 2, 2018 · 6 min read

The calorie theory of obesity has been perhaps one of the greatest failures in the history of medicine. Given the number of excess deaths caused by metabolic syndrome, you could argue that it is a bigger disaster than World War II. It is based on a complete misinterpretation of the energy balance equation.

Body fat gained = Calories In — Calories Out

This equation, known as the energy balance equation is always true. So, looking at this equation, people then say something like ‘It’s all about restricting the calories you eat’, or ‘All diets work by restricting calories’. On the Calories Out side, you hear things like ‘You should exercise more’. This is the standard Eat Less, Move More approach. Doctors, even so-called ‘obesity experts’ and various health professionals say stuff like this all the time, but they’re completely wrong. The problem is that they don’t even know why they’re so wrong.

The energy balance equation (which, yes, is always true) does NOT support the Eat Less, Move More approach. Huh? Let me explain. You can also watch my recent video from NBC here.

Counting Calories is a ridiculous way to try to lose weight

Let’s throw some numbers into the mix to make things more clear. Assume the baseline situation of stable body weight (zero body fat gained or lost) and 2000 calories per day intake.

0 Body Fat = 2000 Calories In — 2000 Calories Out

Calories Out is not just exercise. This is composed of 2 things — resting energy expenditure, or basal metabolic rate (BMR) and exercise. If you assume zero exercise, an average BMR is 2000 calories per day. This energy is used by the heart, lungs, kidneys, generation of body heat etc. Note that BMR is NOT under conscious control. You cannot ‘decide’ that your heart will pump more blood. You cannot ‘decide’ to generate more body heat. No amount of willpower will make your kidneys use more energy.

Exercise is generally a very small portion of the total daily expenditure, unless you are exercising multiple hours in the day. Consider a moderate exercise of 1 hour of moderate walking/ jogging, 3 times per week. Each walk burns approximately 100–200 calories. If you’ve ever exercised on a treadmill with a calorie counter, you’ll know how slowly that meter rises. That 100 calories used during exercise pales in comparison to the 2000 calories eaten on an average day. So, we can safely ignore the effect of exercise except for those who do in excess of 1 hour per day.

So, people suppose that if you decrease your caloric intake by 500 calories per day or 3500 calories per week, that you will lose 1 pound of fat per week assuming that 1 pound of fat contains roughly 3500 calories.

-500 calories = 1500 Calories In — 2000 Calories Out

Please take careful note that in order to lose body fat, Calories Out MUST remain stable. Must. Must. But this is precisely what we know to be FALSE for at least the last 100 years. BMR may increase or decrease 30–40%. This was shown as early as 1917, when studies showed that a reduction of calorie intake by 30% is quickly met by a decrease in BMR by 30%.

Dr. Ancel Keys showed much the same effect in his famous Minnesota ‘starvation study’. Despite the title, subjects were given 1570 calories per day, more than most weight loss regimens being prescribed today. A drop in calories eaten by 40% is met with a 40% drop in BMR.

The reason for this is simple. Your body is very smart and does not want to die. If you do not alter your hormones (predominantly insulin), you won’t be able to access your fat stores. If you can’t get energy from body fat, then then you cannot run an energy deficit forever. If you are only taking in 1500 calories, you can only spend 1500 calories. So what happens in real life experience with the Caloric Restriction as Primary strategy is

0 Body Fat = 1500 Calories In — 1500 Calories Out

Yes. Just as every dieter knows, you start out cutting 500 calories a day and losing weight. Soon, weight plateaus, and you feel like crap, because you are used to burning 2000 calories and now are only burning 1500. So you are generating less body heat (feel cold) and are more tired.

The BMR drop is the main culprit. We’ve known this for over a century. If you cut a few calories every day, your body will burn less calories and you will not lose fat. Weight loss plateaus and then you start to regain weight. So, counting calories, as a strategy for weight loss, has been proven over and over again to fail.

Why can’t you make up the difference with 500 calories of Body Fat? If you reduce the right foods (sugars, refined grains) and don’t eat all the time, then you may very well lose weight successfully. If you reduce calories, but still eat processed junk food and constantly snack, then you keep insulin levels high. Insulin blocks fat burning. Technically, we say that insulin inhibits lipolysis. In other words, keeping insulin high, but lowering calories means we can’t use our body fat stores of energy. So if only 1500 calories comes in, only 1500 calories can be used.

Strategies that lower insulin, however (Low Carb, Intermittent Fasting) are completely different. By lowering insulin, we tell our bodies that there is no food coming in. Therefore, the body switches from burning the calories from food, to burning the calories from our body fat. Our body wants to burn 2000 calories, but it just gets them from body fat instead of food. Instead of restricting energy (calories), our body is switching fuel sources, from food to stored food (body fat). But this can only happen if we correct the underlying hormonal problem of excessive insulin. So is ‘Calories In Calories Out’ totally useless? Well not totally.

You may have heard of or received an email offer for the Nigerian Phishing (email fraud) scam. The story goes like this. A few years ago, some crooks would send out millions of emails to potential marks (victims). The emails would say that they were an exiled Nigerian prince that was forced to flee out of his home country. He had $10 kajillion dollars in the bank and offered to split it with you if you would only give him your banking information. In other scams, the crooks would ask for money. Send them $1000 dollars and then they could go to the bank, retrieve their $10 billion and give you $2 billion as a thank you. The scam became well known as a fraud and most people recognized it immediately so they simply deleted the email.

However, contrary to what you might expect, the scam did not disappear. I still receive these emails on a regular basis, and they even keep the Nigerian prince rather than change it to, for example, an Indonesian princess. Since almost everybody has heard of this scam, what was the point?

Crooks could immediately identify potential marks by sending out this particular scam. If the crooks made up a new scam, they would receive many replies to their email, but most of them would not be gullible enough to hand over actual cash. By keeping the Nigerian prince scam, they could immediately and efficiently identify the most gullible people who would hand over cash. In this way, the Nigerian prince scam is a great marker for gullibility.

The Calories In/ Calories Out (CICO) model performs the same task for me. The CICO model has been tested over and over again. Multiple trials have shown it to be a complete failure. If somebody vociferously defends the CICO paradigm, I can immediately and efficiently identify them as people who have not really understood what causes obesity, and have no serious grasp of the physiology behind weight gain. These are the people who keep parroting ‘A calorie is a calorie’, as if I had asked them ‘Is a calorie a calorie’? The question I ask is ‘Are all calories equally fattening’, to which they usually stare blankly at me, before replying ‘It’s all about calories’, as if the body had any actual method of measuring calories.

The CICO model very useful because it efficiently flags people who are not all that knowledgable about obesity, and I can safely ignore them. There are many of these people out there, and not everybody is worth listening to.

Calories in vs. Calories out

Factors that influence how many calories we eat: our environment, how many hours of (quality) sleep we get, our emotional state, our body fat percentage, our hormone levels, and our blood sugar levels.

Factors that influence how many calories we burn: exercise (duh), our lean body mass, our balance of gut bacteria, how many hours of sleep we get, our hormone levels, and our immune function.

Here, if we take an even closer look, it’s apparent that the factors that influence our input, can affect the factors that influence our output. For example, high blood sugar levels (or excessive sugar intake) can alter the balance of our gut bacteria. This can make it harder for us to lose weight, and easier for us to crave high fat, high sugar foods. Additionally, lack of sleep can affect our hormone levels, again making it more difficult for us to lose weight, and making it easier for us to crave those high fat, high sugar foods.

I could go on and on, but the point is, even if we calculate every calorie that goes into and our of our bodies, there are still a variety of other metabolic processes that effect both how much we weigh and our general health status. This is why a lot of people who consistently go into cycles of restricting and ‘cheating’ always have trouble finding that harmonious place of weight maintenance.

This is why when I work with my lovely clients we FIRST tackle all of the influencing factors and THEN we talk about calories. (Secret: it rarely ever gets to that point)!

Also, let’s not forget, weight is not the only measure of good health. The truth is no number, metric, or formula is going to be able to give you the whole picture. The only place that really exists is within you.

So before stepping on the scale or thinking of all of the “shoulds” (I should be exercising, I should be eating less), ask yourself some internal feedback questions:

When I wake up in the morning, do I feel happy? Energized?

When I think about eating, how does it make me feel? Excited? Stressed? No Reaction?

What am I hungry for? Why?

Am I full? Am I satisfied?

What am I craving? Why?

All of these questions can be secret doors to figuring out what your body needs to work optimally and can be the beginning of a lifelong practice of feeding your body intuitively. No counting required.

I could go on and on and on about this subject, but I want to turn it over to you. Do you count calories? How has it worked for you? Have you tried any other measures or methods to help lose or maintain weight? Increase your energy levels? Let me know in the comments below.

Calories In = Calories Out is BS

July 17, 2018 General Interest

I posted an image on social media a few weeks ago stating “Calories In = Calories Out is Bullsh*t” and it was met with a massive response.

I had a sense it’d strike a chord and it sure did. One of the dominant themes I heard from students and professionals was, “It is BS, BUT it’s what I was taught in school!” And even more disheartening, I got this message from students, interns, and recent grads. This left me both depressed and eager to do a little bit of myth busting here.

First, a rant.

The mantra “calories in = calories out” is unhelpful because it assumes our bodies can be worked over like a math calculation. It can’t. I’ll never forget my first year as a dietitian. I was busy preparing a workshop and the book I had bought to help me prepare listed examples like this:

  • Remove 1 Tb of butter/day and lose 10 pounds in 1 year
  • Swap 1 oz of chocolate for 2 TB jelly beans and lose 5 pounds in 1 year

These kinds of dieting messages are useless because it assumes you eat the same exact number of calories every day and that subtracting a specific number of calories will lead to a consistent caloric deficit. That’s not how it works when you’re human. This message is also harmful because it’s misleading. It gives the false notion that if you count your calories precisely (spoiler: you can’t) and exercise enough willpower (spoiler: willpower dooms us all), you can simply write up a math calculation to get yourself to your chosen weight. None of this is possible and here’s why.​​​​​​​

The Math is Incomplete

Of course our body weight is impacted by what we eat and how our body uses that fuel. But it’s also influenced by a host of other complex mechanisms that we have very little control over, thanks to the genetics passed along from our parents. Most importantly, attempts to decrease intake and increase output creates a massive change in our physiology that undermines efforts to down-regulate our weight. This includes but is not limited to:

  1. Basal metabolic rate: This accounts for about 70% of our metabolic activity and decreases as weight is lost.
  2. Appetite hormones like leptin and ghrelin: Turns out that, as a person loses weight, the body shifts the production of these hormones to encourage increased intake.
  3. Changes in the reward system in the brain: For you neuroscience geeks, it’s particularly related to the orbital frontal cortex, which is related to the reward pathways in our brain making sure we seek out more food and don’t die of famine.

Consequently, when we try to alter calories in, calories out, there are a host of other “numerics” that step in to complicate the equation. However, an important note is that the way and the degree to how these responses happen in you body is outside of your control and largely dictated by genetics.

What I Am Not Saying

I am not saying it is impossible to increase or decrease your weight by changes to what you eat and how you move. I AM saying that manipulating one’s weight is not as simplistic as calories in = calories out and reducing our experience to such an incomplete equation is both false and harmful. It also fails to explain why the vast majority of people regain lost weight. This is largely due to the mechanisms I listed above.

“Re-Thinking Thin”

The book, “Rethinking Thin” by Gina Kolata, changed my view on weight regulation when I read it over a decade ago. She cited research done by “obesity” researchers back in the 80’s. In brief, participants were fed calorie-controlled diets and were only allowed to move in highly controlled ways. The researchers assumed that this would prove that “obese” individuals simply had a willpower issue. Nope. The results were shocking. Even though calorie levels were the exact same for the participants, they lost, gained, and maintained massively different weights. The light bulbs flicked on and they realized something else must have been happening in the equation of weight regulation. And this explains why humans can consume very similar amounts of food and look differently! We are designed for diversity – height, hair color, skin color, and weight.

If you are looking for an even deeper dive into this topic, I can highly recommend the research of Dr. Michael Rosenbaum, whose talk on “The Metabolic Changes that Occur with Weight Loss,” provided me with up-to-date science when I heard him speak at an eating disorders conference a few years ago. I’ll provide citations below. Ironically, it’s the work of “obesity researchers” that continues to inform my non-weight centered approach to health and well-being.

References to Consider:

  • Models of energy homeostasis in response to maintenance of reduced body weight
  • Effects of reduced weight maintenance and leptin repletion on functional connectivity of the hypothalamus in obese humans
  • Brain reorganization following weight loss

My Message Isn’t Sexy

I am acutely aware of how NOT sexy my message is. We can’t control our bodies in ways we’d like to believe – at least not without consequence.

But by engaging in balanced, sustainable, kind, and pleasurable exercise and eating, our body size will sort itself out. Anything beyond that is likely to drive you up a wall.

Calories In – Calories Out


There is general agreement that the US, and the West in general, is in the midst of an obesity epidemic. Even if you think this is alarmist or overstating the situation, the data clearly shows a steady expansion of the American waistline. Weight loss is a multi-billion dollar industry and is an active area of research, and yet all the self-help books, low-carb diets, and whole grain foods do not seem to be translating into successful weight loss for the public. Why is this?

From my perspective the failure of the weight-loss industry and public health measures is due to a failed approach – focusing on factors that have a small overall effect on weight loss while neglecting those that have a huge impact.

From an individual perspective, weight loss is simple (although not easy). It is a matter of calories in vs calories out – you cannot escape this equation. This means eating less and moving more. Simple, basic strategies to help reduce caloric intake seem to be the most effective. This means portion control, and limiting calorie-dense foods. The latter requires knowing how many calories are in food you are likely to consume (that Starbucks Mocha Breve has 580 calories). Limiting total caloric intake also means keeping track of how much you eat – which is deceptively difficult to do. Most people fail on diets because they simply underestimate their total caloric intake.

A recent study published in American Journal of Preventive Medicine showed that simply keeping a daily diary of food intake doubled total weight loss in a 5 month study (participants who kept a diary lost an average of 17.5 pounds). This is a significant difference, and the amount of weight lost was also significant. This supports other evidence that methods for estimating and keeping track of caloric intake are very predictive of successful weight loss.

And yet this huge effect from a simple technique was overshadowed in the media by another recent study that showed that those on a low carb diet lost an extra four pounds over 2 years over low-fat dieters (for a total of about 10 pounds). Wow – 4 pounds over 2 years. The media touted this as vindication for low-carb dieting, when it really showed that the diets did not work very well, and any differences among them were practically insignificant.

Now we are told that a pill can reproduce the effects of exercise. The media hails this as a boon to couch potatoes. It did not take long, however, for others to point out that the studies performed on mice did not consider many of the known benefits of exercise. At least for now, there is no exercise in a pill.

The pattern is clear – the media thinks (and they may be right) that the public is interested in learning how to lose weight without calorie restriction and exercise. They would rather eat different food than less food, and exercise “smart” rather than frequently. But the data does not comply.

By obsessing over effects so small that it is controversial if they even exist, and if they do their impact would be minor – the media and self-help industry are likely worsening the obesity problem. Rather there should be an emphasis first on what does work. Here is a quick summary: (Standard disclaimer – this is for information only, not individual medical advise. Many people have individual health concerns that affect their diet and ability to exercise, so if necessary consult your physician.)

– Eat fewer calories. Do this by:

– Choosing lower calorie and less calorie dense food, and by avoiding large calorie extras.

– Avoid drinking calories.

– Use portion control (just don’t take that second helping).

– Track your food intake with a convenient and simple system, at least until you get a better feel for where your calories are coming from.

– Increase your calorie output by exercising more, at least three days a week, but more is better.

– Do something you enjoy as you are much more likely to keep up with it. Likewise, make it as convenient as possible.

– Little activities add up, so take the stairs when you can, walk when you can, and spend more time in recreation that involves moving rather than sitting.

– Weigh yourself weekly to assess how you are doing so you can make adjustments as necessary.

Those are the basics – you should at least start with these steps. The goal is long-term weight control, not a quick fix. That is the other problem with most “diets”- they emphasize short term weight loss rather than long term health and weight control. Forget about highly restrictive diets – no one sticks with them. Forget about really complex diet plans – no one sticks with them. Forget about plans where you have to buy special food – no one sticks with them.

Basically – do not think to yourself, “I just need to get these X pounds off then I can switch to long term maintenance.” The problem with this approach is that almost everyone gains all the weight back. You are better off just going to the long term plan initially – don’t be lured by the promise of rapid weight loss.

From a public health perspective the issues are more challenging. Education can help individuals, but does not have a huge statistical impact on the public. Measures that are helpful are those that make better food choices easier. At my hospital cafeteria, for example, the sandwich counter used to offer two choices for sides, pretzels or potato chips. That was it. Now they off carrot sticks or celery, so that’s what I get. The default choice contains many fewer calories. Those types of measures work.

The trend in marketing, however, has been counter productive. Products are promoted as low-fat or low-carb (depending on your preference) – but neither are necessarily low calorie. They simply replace fat calories with carbs, or vice versa. So people end up eating more total calories because they think they are eating healthy. It’s counter productive. Printing nutritional information on the side of the package is nice, but it hasn’t helped.

Bottom line time

The public would be better off if they completely ignored the weight loss industry, avoided self-help weight loss books and diets, and simply focussed on some basic principles, as outlined above. Public health measures should focus on making default choices more healthful and lower calorie. We are starting to see a trend in this direction, in response to public demand. You can now get apple slices instead of french fries as a side in your kid’s Happy Meal. I can get carrot sticks instead of potato chips with my tuna on rye. But if there is going to be a reversal of the obesity trend in the West much more has to be done.


Managing Your Weight: Calories In vs. Calories Out

There are a number of competing equations to calculate your Resting Metabolic Rate (RMR) – the number of calories your body burns at rest in a single day. While these formulas offer a ballpark number of calories you can eat based on your age and weight, the most commonly used equations come from decades-old research. In fact, one study found the formulas to be off by as much as 15 percent, especially in obese individuals. All equations, even those based on body composition, can over- or underestimate the number of calories you should eat.

When scientists who study metabolism need to get it right, they rely on a “metabolic cart” – an elaborate tool that calculates RMR based on the amount of oxygen you breathe in and carbon dioxide you exhale. In the past, this kind of technology was expensive and inaccessible, but for $40- $100, you can get results via a simple, hand-held breath test that is used for metabolic assessment at gyms and spas nationwide.

To calculate your RMR on your own, follow this equation:

* Multiply your healthy weight by 10 calories for your RMR. Example: You weigh 150 but 140 is a healthier weight for you. Multiply 10 calories x 140 pounds (appropriate weight) = 1,400 calories for your RMR.

* To your RMR, add half that number (assuming you are moderately active throughout the day). Example: 50% x 1,400 calories for RMR = 700 calories for daily activity.

You can increase your activity to burn 200 more calories; then eat 300 fewer calories to cut the 500 calories. Use this plan and you’ll lose 1/2-1 pound per week.

How Many Calories Should You Eat per Day to Lose Weight?

Calories are simply a measure of energy.

It’s a known fact that to gain weight, more calories need to be entering your body than leaving it.

Conversely, you lose weight if more calories leave your body than enter it.

That said, cutting calories without taking the foods you eat into account is usually not a sustainable way to lose weight.

Though it works for some people, most end up hungry and eventually give up on their diet.

For this reason, it’s highly recommended to make a few other permanent changes to help you maintain a calorie deficit in the long term, without feeling starved.

Here are 5 evidence-based diet and lifestyle changes that have been shown to help people lose weight.

1. Eat more protein

When it comes to losing weight, protein is the king of nutrients.

Adding protein to your diet is the simplest, most effective, and most delicious way to lose weight with minimal effort.

Studies show that protein both increases your metabolic rate and helps curb your appetite (3).

Because protein requires energy to metabolize, a high protein diet can increase calories burned by 80–100 calories per day (4, 5, 6).

Protein is also by far the most filling nutrient. One study showed that people who ate 30% of calories from protein automatically ate 441 fewer calories per day (7).

In other words, you can easily increase calories out and reduce calories in just by adding protein to your diet.

Protein can also help fight cravings, which are a dieter’s worst enemy.

In one study, consuming 25% of daily calories from protein reduced obsessive thoughts about food by 60% and cut the desire for late-night snacking by 50% (8).

If you want to lose weight sustainably and with minimal effort, consider making a permanent increase in your protein intake.

It will not only help you lose weight but also prevent ⁠— or at least significantly reduce ⁠— weight regain (9, 10).

Summary Increasing your protein intake can boost metabolism, fight cravings, and significantly reduce appetite. This can lead to automatic weight loss.

2. Avoid sugary soft drinks and fruit juices

Another relatively easy change you can make is to eliminate liquid sugar calories from your diet.

This includes sodas, fruit juices, chocolate milk, and other beverages with added sugar.

These products are among the most fattening aspects of the modern diet, as your brain doesn’t register liquid calories in the same way as it registers solid calories.

For this reason, drinking sugary soda doesn’t make your brain automatically compensate by having you eat smaller amounts of other things instead (11, 12).

Studies have shown that sugary drinks are strongly linked to an increased risk of obesity, with one study in children showing a 60% increased risk for each daily serving of a sugar-sweetened beverage (13).

Of course, the harmful effects of sugar go beyond weight gain. It can have disastrous effects on metabolic health and raise your risk of many diseases (14).

Though small amounts of natural sugars from foods like fruit are fine, large amounts from added sugar and sugary drinks can harm your health in a variety of ways.

There is no physiological need for these beverages, and the long-term benefits of avoiding them can be enormous.

Summary It’s important to avoid sugary soft drinks and fruit juices, as liquid sugar is the single most fattening aspect of the Western diet.

3. Drink more water

One very simple trick to increase weight loss is to drink more water.

Doing so can increase the number of calories you burn for up to 90 minutes (15, 16).

Drinking about 8 glasses (equal to 68 ounces or 2 liters) of water per day can make you burn about 96 more calories.

However, the timing of when you drink water may be even more important, as having it before meals can help reduce hunger and make you automatically eat fewer calories (17).

In one 12-week study, drinking 17 ounces (0.5 liters) of water half an hour before meals made people lose 44% more weight (18).

When combined with a healthy diet, drinking more water (especially before meals) appears to be helpful if you need to lose weight.

Caffeinated beverages, such as coffee and green tea, are also excellent. Their caffeine content can somewhat boost metabolism, at least in the short term (19, 20).

Summary Studies have shown that drinking water can boost metabolism. Drinking it half an hour before meals can help you eat fewer calories.

4. Exercise and lift weights

When you eat fewer calories, your body compensates by saving energy, making you burn less.

This is why long-term calorie restriction can significantly reduce metabolism.

Plus, it can lead to loss of muscle mass. Muscle is metabolically active, so this can reduce metabolism even further.

The only proven strategy to prevent this effect is to exert your muscles by lifting weights.

This has been repeatedly shown to prevent muscle loss and stop your metabolism from slowing during long-term calorie restriction (21, 22).

Of course, if you’re trying to lose weight, you don’t want to just lose fat, you also want to make sure that you take care of your muscles.

If you can’t get to a gym, consider doing bodyweight exercises, such as push-ups, squats, and sit-ups, at home.

Doing some cardio, including walking, swimming, or jogging, can also be important — not necessarily for weight loss but for optimal health and general well-being.

What’s more, exercise has a variety of other benefits that go beyond weight loss, such as longevity, lower risk of disease, more energy, and feeling better every day (23, 24, 25).

Summary Lifting weights is important, as it reduces muscle loss and prevents your metabolic rate from slowing.

5. Reduce your carb intake

Cutting carbs is a very effective way to lose weight, as it reduces appetite and makes you eat fewer calories automatically (26, 27, 28).

Studies have shown that eating a low carb diet until fullness can make you lose about two to three times more weight than a calorie-restricted, low fat diet (29, 30, 31).

Not only that, but low carb diets also have many other benefits for health, especially for people with type 2 diabetes or metabolic syndrome.

But you don’t have to go low-carb. Simply ensure that you eat quality, fiber-rich carb sources, focusing on whole, single-ingredient foods.

If you stick to whole foods, the exact composition of your diet becomes less important.

Summary Cutting carbs may aid weight loss by reducing appetite and making you eat fewer calories.

One of the most commonly held diet myths is “To lose one pound of fat you need to create a deficit of 3,500 calories”. This is wrong at every level. First of all, one pound does not equal 3,500 calories, as we will show below. You will see this formula in government literature, in just about every diet book, in private health booklets and all over the internet. The next time you see it, or hear it, ask where it comes from. You will not get an answer. (I asked the following seven UK organisations: the National Health Service (NHS); the National Institute for Clinical Excellence (NICE); the Department of Health; the National Obesity Forum; the Association for the Study of Obesity; the British Dietetic Association and Dieticians in Obesity Management and five of these have no idea where it even comes from. The two that tried to prove it failed by a factor of about ten.) (I’ve since put this up as a full blog post).

The first part of the calorie formula is the assertion that one pound of fat contains 3,500 calories. You will struggle to find anyone who can demonstrate the precise calculation behind this, so I’ll offer this as a suggestion:

1) One pound equals 454 grams (decimal places aside, this is a fact);

2) Fat has nine calories per gram (this is the universally accepted conversion, but it is an estimate and significantly rounded down from even the original estimate);

3) Human fat tissue is approximately 87% lipid (this is a widely accepted conversion, but it is also an estimate).

Putting these together, we can derive the sum that 454 grams of body fat tissue has approximately the calorific energy of 395 grams of pure fat (454 grams x 87%), that is 3,555 calories (395 grams x 9).

3,555 is close enough to 3,500 you may think, until you see the absurdity of how precisely the formula is applied. The National Obesity Forum web site states “one less (sic) 50 calorie plain biscuit per day could help you lose 5lbs (2.3kg) in a year – and one extra biscuit means you could gain that in a year!” (Ref 1) No it won’t. I can’t even get an estimate of the formula to closer than 55 calories ‘out’.

With little effort I can find evidence in obesity journals that fat has anywhere between 8.7 (Ref 2) and 9.5 (Ref 3) calories per gram. The same obesity journal that says that human fat tissue can be 87% lipid also says that it may be 72% lipid (Ref 4).

Taking the extremes of these, we can establish a range whereby one pound of fat could contain anywhere between 2,843 and 3,752 calories. Given that it is currently held that one pound is 3,500 calories we could (according to this formula) inadvertently gain six stone every year at the low end of the calculation and lose almost two stone in the same year if one pound is 3,752 calories. The 3,750 calories is the assumption held in this classic article (Ref 3). Don’t worry about any of this – because the formula doesn’t hold at any other level either. (Please see footnote for calculation).

Ref 1:

Ref 2: Dr. Geoffrey Livesey, “The Calorie Delusion: Why food labels are wrong”, New Scientist, (15 July 2009). FAO Food & Nutrition paper 77: “Food energy – methods of analysis and conversion factors”, Report of a Technical Workshop, Rome, (December 2002).

Ref 3: Max Wishnofsky, “Caloric equivalents of gained or lost weight”, The American Journal of Clinical Nutrition, (1958).

Ref 4: Bozenraad, Deutsche Archives Internal Medicine, (1911).


This calculation is done as follows: It assumes that a person can maintain weight at a daily intake of the calories assumed to equal one pound of fat. If we think one pound equals 3,500 calories and in fact one pound equals 2,843 calories, over a year, 657 ‘extra’ calories a day, simply from the formula ‘being wrong’, would add up to 239,805 extra calories and this, divided by 2,843 gives 84 pounds, or six stone. Adjust the calculations for women more typically maintaining at 2,000 calories a day and men more typically at 2,600 calories a day and the inaccuracy of the formula still creates wide disparity.

Calories in vs out

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