Whey Stimulates Insulin …

The hormonally powerful part of milk is not the fat or the milk sugar (lactose), but the whey:

Dairy, meat and the insulin index proteins differ greatly in their capacity to stimulate insulin, with dairy products in particular being potent stimuli. Dairy also shows the largest discrepancy between the blood glucose and insulin effect. It scores extremely low on the glycemic index (15 to 30), but very high on the insulin index (90 to 98). Milk does contain sugars, predominantly in the form of lactose. However, when tested, pure lactose has minimal effect on either the glycemic or insulin indexes. Milk contains two main types of dairy protein: casein (80 percent) and whey (20 percent). Cheese contains mostly casein. Whey is the byproduct left over from the curds in cheese making. Bodybuilders frequently use whey protein supplements because it is high in branched-chain amino acids, felt to be important in muscle formation. Dairy protein, particularly whey, is responsible for raising insulin levels even higher than whole-wheat bread, due largely to the incretin effect.

… But Whey’s Stimulation of Incretin Is Also Very Satiating

Like many people, I find whole milk very satisfying, and crave other food a lot less after a glass of milk. There is a hormonal reason for this. Jason Fung explains:

But are dairy and meat are fattening? That question is complicated. The incretin hormones have multiple effects, only one of which is to stimulate insulin. Incretins also have a major effect on satiety. … Incretin hormones play an important role in the control of gastric emptying. The stomach normally holds food and mixes it with stomach acid before slowly discharging the contents. GLP-1 causes stomach emptying to significantly slow. Absorption of nutrients also slows, resulting in lower blood glucose and insulin levels. Furthermore, this effect creates a sensation of satiety that we experience as “being full.” A 2010 study compared the effect of four different proteins: eggs, turkey, tuna and whey protein—on participants’ insulin levels. As expected, whey resulted in the highest insulin levels. Four hours afterward, participants were treated to a buffet lunch. The whey group ate substantially less than the other groups. The whey protein suppressed their appetites and increased their satiety. In other words, those subjects were “full.” …

So the incretin hormones produce two opposing effects. Increased insulin promotes weight gain, but increased satiety suppresses it—which is consistent with personal experience.

On Net, Whole Milk Aids Weight Control. Low-Fat Milk is Neutral

Airtight experimental evidence on the net effect of milk is not available, but there is some associational evidence suggesting that whole milk aids in weight control:

These two opposing effects—insulin promotes weight gain, but satiety promotes weight loss—cause a maddening debate about meat and dairy. The important question is this: Which effect is more powerful? …

The story with dairy is entirely different. Despite the fact that its consumption causes big increases in insulin levels, large observation studies do not link dairy to weight gain. If anything, dairy protects against weight gain, as found in the Swedish Mammography Cohort. In particular, whole milk, sour milk, cheese and butter were associated with less weight gain, but not low-fat milk. The ten-year prospective CARDIA Study found that the highest intake of dairy is associated with the lowest incidence of obesity and type 2 diabetes. Other large population studies confirmed this association. The data from the Nurses’ Health Studies and the Health Professionals Follow-up Study shows that overall, average weight gain over any four-year period was 3.35 pounds (1.5 kilograms)—pretty close to 1 pound per year. Milk and cheese were essentially weight neutral.

Yogurt is an important case to talk about because so many people think that yogurt is a health food. Plain full-fat yogurt should be just as good for weight loss as whole milk if not a bit better, but the low-fat, high-sugar yogurt many people eat is bad stuff. It is unlikely that the good effects of the yogurt content are able to overcome the bad effects of the added sugar.

Reigning Dietary Theories as Reflected in the Supermarket May Be Off Target

Going down the aisles of grocery stores, I notice first all the aisles that are temples to refined carbohydrates. Then when I look closer at things that claim to be especially healthy foods, I notice many low-fat products (see “Jason Fung: Dietary Fat is Innocent of the Charges Leveled Against It”) and dairy-free products. These may not be the most important directions to go (except for those with lactose intolerance or another specific milk intolerance).

Zero added sugar of any type and no artificial sweeteners is likely to be a more helpful direction to go for health. (See Sugar as a Slow Poison.) Of course, ruling out added sugar and artificial sweeteners rules out a large share of all processed foods, which may be helpful in its own right given the incentives manufactures have to maximize taste and shelf-life with little regard for health other than doing the minimum to be able to pretend something is healthy.

Milk may be only a few thousand years old as a common food for adult humans, and then only in some ancestries. But a few thousand years in some ancestries is a lot longer and more broadly tested than many of the processed foods advertised today have been tested. I recommend worrying more about new types of processed foods that are less than 200 years old in widespread consumption than about whole milk.

Don’t miss my other posts on diet and health:

I. The Basics

  • 3 Achievable Resolutions for Weight Loss

  • Stop Counting Calories; It’s the Clock that Counts

  • Lisa Drayer: Is Fasting the Fountain of Youth?

  • Jason Fung’s Single Best Weight Loss Tip: Don’t Eat All the Time

  • 4 Propositions on Weight Loss

  • Forget Calorie Counting; It’s the Insulin Index, Stupid

  • Obesity Is Always and Everywhere an Insulin Phenomenon

  • Why a Low-Insulin-Index Diet Isn’t Exactly a ‘Lowcarb’ Diet

  • What Steven Gundry’s Book ‘The Plant Paradox’ Adds to the Principles of a Low-Insulin-Index Diet

  • The Problem with Processed Food

  • On Exercise and Weight Loss

  • David Ludwig: It Takes Time to Adapt to a Lowcarb, Highfat Diet

II. Sugar as a Slow Poison

  • Yes, Sugar is Really Bad for You

  • Best Health Guide: 10 Surprising Changes When You Quit Sugar

  • Letting Go of Sugar

  • Heidi Turner, Michael Schwartz and Kristen Domonell on How Bad Sugar Is

  • Which Is Worse for You: Sugar or Fat?

  • Does Sugar Make Dietary Fat Less OK?

  • Sugar as a Slow Poison

  • How Sugar Makes People Hangry

  • Michael Lowe and Heidi Mitchell: Is Getting ‘Hangry’ Actually a Thing?

  • Ken Rogoff Against Sugar and Processed Food

III. Anti-Cancer Eating

  • How Fasting Can Starve Cancer Cells, While Leaving Normal Cells Unharmed

  • Why You Should Worry about Cancer Promotion by Diet as Much as You Worry about Cancer Initiation by Carcinogens

  • Good News! Cancer Cells are Metabolically Handicapped

  • How Sugar, Too Much Protein, Inflammation and Injury Could Drive Epigenetic Cellular Evolution Toward Cancer

  • Meat Is Amazingly Nutritious—But Is It Amazingly Nutritious for Cancer Cells, Too?

  • My Annual Anti-Cancer Fast

IV. Eating Tips

  • Our Delusions about ‘Healthy’ Snacks—Nuts to That!

  • My Giant Salad

  • Using the Glycemic Index as a Supplement to the Insulin Index

  • The Keto Food Pyramid

  • Hints for Healthy Eating from the Nurse’s Health Study

  • Carola Binder—Why You Should Get More Vitamin D: The Recommended Daily Allowance for Vitamin D Was Underestimated Due to Statistical Illiteracy

  • Eating on the Road

  • Intense Dark Chocolate: A Review

  • In Praise of Avocados

  • Putting the Perspective from Jason Fung’s “The Obesity Code” into Practice

  • Which Nonsugar Sweeteners are OK? An Insulin-Index Perspective

  • Black Bean Brownies

  • On Food Preparation Memes

  • Christmas Dinner 2018 with the Kimballs in Colorado

  • Freakonomics: The Story of Bananas

V. Calories In/Calories Out

  • Nina Teicholz on the Bankruptcy of Counting Calories

  • Mass In/Mass Out: A Satire of Calories In/Calories Out

  • How the Calories In/Calories Out Theory Obscures the Endogeneity of Calories In and Out to Subjective Hunger and Energy

  • The Trouble with Most Psychological Approaches to Weight Loss: They Assume the Biology is Obvious, When It Isn’t

  • How Low Insulin Opens a Way to Escape Dieting Hell

  • Kevin D. Hall and Juen Guo: Why it is so Hard to Lose Weight and so Hard to Keep it Off

VI. Other Health Issues

  • How Not Getting Enough Sleep Messes You Up, Part 1

  • Fighting the Common Cold

VII. Wonkish

  • Evidence that High Insulin Levels Lead to Weight Gain

  • Framingham State Food Study: Lowcarb Diets Make Us Burn More Calories

  • Anthony Komaroff: The Microbiome and Risk for Obesity and Diabetes

  • Evidence that Gut Bacteria Affect the Brain

  • Prevention is Much Easier Than Cure of Obesity

  • A Conversation with David Brazel on Obesity Research

  • Don’t Tar Fasting by those of Normal or High Weight with the Brush of Anorexia

  • Magic Bullets vs. Multifaceted Interventions for Economic Stimulus, Economic Development and Weight Loss

  • Carola Binder: The Obesity Code and Economists as General Practitioners

  • The Heavy Non-Health Consequences of Heaviness

  • After Gastric Bypass Surgery, Insulin Goes Down Before Weight Loss has Time to Happen

  • Biohacking: Nutrition as Technology

  • A Low-Glycemic-Index Vegan Diet as a Moderately-Low-Insulin-Index Diet

  • David Ludwig, Walter Willett, Jeff Volek and Marian Neuhouser: Controversies and Consensus on Fat vs. Carbs

  • Analogies Between Economic Models and the Biology of Obesity

  • Layne Norton Discusses the Stephan Guyenet vs. Gary Taubes Debate (a Debate on Joe Rogan’s Podcast)

  • Sutton, Beyl, Early, Cefalu, Ravussin and Peterson: Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes

  • Critiquing `All-Cause and Cause-Specific Mortality with Low-Carbohydrate Diets’ by Mohsen Mazidi, Niki Katsiki, Dimitri P. Mikhailidis, Naveed Sattar and Maciej Banach

VIII. Debates about Particular Foods and about Exercise

  • Exorcising the Devil in the Milk

  • How Important is A1 Milk Protein as a Public Health Issue?

  • Is Milk OK?

  • ‘Is Milk Ok?’ Revisited

  • Whole Milk Is Healthy; Skim Milk Less So

  • Jason Fung: Dietary Fat is Innocent of the Charges Leveled Against It

  • Faye Flam: The Taboo on Dietary Fat is Grounded More in Puritanism than Science

  • Salt Is Not the Nutritional Evil It Is Made Out to Be

  • Confirmation Bias in the Interpretation of New Evidence on Salt

  • Eggs May Be a Type of Food You Should Eat Sparingly, But Don’t Blame Cholesterol Yet

  • Julia Belluz and Javier Zarracina: Why You’ll Be Disappointed If You Are Exercising to Lose Weight, Explained with 60+ Studies (my retitling of the article this links to)

IX. Gary Taubes

  • Vindicating Gary Taubes: A Smackdown of Seth Yoder

  • The Case Against Sugar: Stephan Guyenet vs. Gary Taubes

  • The Case Against the Case Against Sugar: Seth Yoder vs. Gary Taubes

  • Diseases of Civilization

  • Gary Taubes Makes His Case to Nick Gillespie: How Big Sugar and a Misguided Government Wrecked the American Diet

  • Against Sugar: The Messenger and the Message

  • Kearns, Schmidt and Glantz—Sugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents

X. Twitter Discussions

  • Putting the Perspective from Jason Fung’s “The Obesity Code” into Practice

  • ‘Forget Calorie Counting. It’s the Insulin Index, Stupid’ in a Few Tweets

  • On Fighting Obesity

  • Debating ‘Forget Calorie Counting; It’s the Insulin Index, Stupid’

  • Analogies Between Economic Models and the Biology of Obesity

  • How the Calories In/Calories Out Theory Obscures the Endogeneity of Calories In and Out to Subjective Hunger and Energy

XI. On My Interest in Diet and Health

See the last section of “Five Books That Have Changed My Life” and the podcast “Miles Kimball Explains to Tracy Alloway and Joe Weisenthal Why Losing Weight Is Like Defeating Inflation.” If you want to know how I got interested in diet and health and fighting obesity and a little more about my own experience with weight gain and weight loss, see “Diana Kimball: Listening Creates Possibilities” and my post “A Barycentric Autobiography. I defend the ability of economists like me to make a contribution to understanding diet and health in “On the Epistemology of Diet and Health: Miles Refuses to `Stay in His Lane’.”

Skim Milk Officially Sucks for More Reasons Than One

Skim milk has always seemed like the obvious choice, right? It has the same vitamins and nutrients as whole milk, but without all the fat. While that may have been commonplace thinking for a while, recently more and more studies suggest that full-fat milk is a better alternative to the fat-free stuff. In fact, some research suggests people who consume full-fat dairy weigh less and are at lower risk for developing diabetes, too, according to a new study published in the journal Circulation.

Tuft University researchers looked at the blood of 3,333 adults during a 15-year period. Turns out, people who consumed more full-fat dairy products, such as whole milk (marked by higher levels of particular biomarkers in their blood) had a 46 percent lower risk of getting diabetes during the study period than those with lower levels of those biomarkers. While the mechanism of how fat reduces the risk of diabetes is still unclear, the correlation is an important one, and at its simplest, may suggest that full-fat dairy is more filling, so you’ll eat less throughout the course of the day, consuming fewer calories overall. (Want more healthy, fatty foods? Try these 11 High-Fat Foods a Healthy Diet Should Always Include.)

Skim milk is also higher on the glycemic index (GI) scale than whole milk by a solid five points, which could explain why it’s associated with a greater risk of diabetes risk. GI is a measurement of how fast a carbohydrate breaks down into glucose in the body and therefore how quickly your blood sugar rises or falls. Plus, did you know that consuming skim milk can actually impact your skin, too? A 2007 study published in the American Journal of Clinical Nutrition found that a low-GI diet can help clear up acne, and a high-GI diet may hinder collagen production (collagen keeps you looking young).

Also on board with the high-fat trend is Nitin Kumar, M.D., a Harvard-trained physician who is board-certified in obesity medicine, who says that the most recent study published in Circulation “is in line with others showing a paradoxical effect of dairy fat on diabetes, and related studies that show that dairy fat may be associated with less weight gain,” a notable change in direction from the skim-milk proponents of the 80’s and 90’s.

So with full-fat dairy products doing a body so good, we’re wondering why the government’s dietary guidelines on MyPlate still suggest low- or fat-free dairy as part of a healthy diet. “The core finding in Circulation study-that dairy fat may prevent the incidence of diabetes-should be confirmed before policy changes are made,” says Kumar. ” can be used to guide future studies.”

We shouldn’t expect the government to make sweeping changes based on this small (but growing!) body of research ASAP, but it looks like a push for full-fat dairy is in the cards. “There is a lot of conventional wisdom about weight loss and metabolic disease that is not based on science, and a lot of myths will be dispelled as modern medicine shines a light on how the body handles nutrients and adapts to dietary changes and weight loss,” Kumar adds. So while you certainly shouldn’t overhaul your diet every time a new study comes out, it’s more than fair to say that you can (and should) go ahead and have that mozzarella appetizer and pour whatever kind of milk you want in your next bowl of oatmeal. You can also try in one of these Chocolate Smoothies You Won’t Believe Are Healthy.

  • By Rachel Jacoby Zoldan @rjacoby13

Inconsistency between glycemic and insulinemic responses to regular and fermented milk products

ABSTRACT

Background: Foods with a low glycemic index are increasingly being acknowledged as beneficial in relation to the insulin resistance syndrome. Certain organic acids can lower the glycemic index of bread products. However, the possible effect of acids in fermented milk products on the glycemic index and on insulinemic characteristics has not been addressed. The metabolic effects of fermented milk or pickled products used as additives to mixed meals have also not been addressed.

Objectives: One objective was to characterize the glycemic and insulinemic responses after intake of regular or fermented milk products (study 1). In addition, the acute metabolic effect of fermented milk (yogurt) and pickled cucumber as supplements to a traditional breakfast based on a high–glycemic index bread was evaluated (study 2).

Design: Ten healthy volunteers were served different breakfast meals after an overnight fast. Capillary blood samples were collected before and during 2 (study 1) or 3 (study 2) h after the meal. White-wheat bread was used as a reference meal in both studies.

Results: The lactic acid in the fermented milk products did not lower the glycemic and insulinemic indexes. Despite low glycemic indexes of 15–30, all of the milk products produced high insulinemic indexes of 90–98, which were not significantly different from the insulinemic index of the reference bread. Addition of fermented milk (yogurt) and pickled cucumber to a breakfast with a high–glycemic index bread significantly lowered postprandial glycemia and insulinemia compared with the reference meal. In contrast, addition of regular milk and fresh cucumber had no favorable effect on the metabolic responses.

Conclusions: Milk products appear insulinotropic as judged from 3-fold to 6-fold higher insulinemic indexes than expected from the corresponding glycemic indexes. The presence of organic acids may counteract the insulinotropic effect of milk in mixed meals.

INTRODUCTION

The glycemic index was introduced to classify carbohydrate foods according to their effect on postprandial glycemia (1). The glycemic index is defined as the incremental blood glucose area after ingestion of a test product, expressed as a percentage of the corresponding area after a carbohydrate-equivalent load of a reference product (glucose or white bread). The insulinemic index can be calculated from the corresponding incremental insulin areas.

Accumulating data now suggest that a diet with a low glycemic index improves blood glucose control, the blood lipid profile, and fibrinolytic activity (2), suggesting a therapeutic role in the treatment of diseases related to insulin resistance. Epidemiologic studies also imply that such a diet may reduce the risk of type 2 diabetes (3, 4) and myocardial infarction (5). Possibly, the lowered insulin demand generally accompanying low–glycemic index foods (6) is the key feature involved. Consequently, even a short duration of hyperinsulinemia may induce insulin resistance in healthy subjects (7).

Today, there is an international consensus regarding the nutritional relevance of the glycemic index concept. In dietary recommendations from the Food and Agriculture Organization and the World Health Organization (8), an increased consumption of low–glycemic index foods is strongly advocated. Pasta (9), legumes (10), and products based on whole cereal grains (11) are examples of commercially available low–glycemic index foods. Unfortunately, most breakfast cereals and conventional bread products belong to the group of foods that elicit high metabolic responses (12). However, it is possible to reduce the insulinemic and glycemic effects of these foods, depending on the raw materials and processes used. It is known that the use of whole cereal grains (13) and sourdough fermentation (14) in bread making produces bread products with lower glycemic indexes.

Lactic acid was shown previously to lower both the glycemic and insulinemic indexes in sourdough bread (14), and inclusion of the sodium salt of propionic acid to a whole-meal barley bread was previously reported to lower the postprandial metabolic response (15). In addition, when vinegar was served as a supplement to a starchy meal, both glycemia and the insulin demand were reduced (16). It can, therefore, be concluded that the presence of certain organic acids in foods, whether generated through fermentation or added, may lower postprandial glycemia and insulinemia.

In most of the Scandinavian countries, both regular and fermented milk products are important items at breakfast. In a previous study with energy-equivalent cereal-based breakfasts, the inclusion of milk did not affect the glycemic index but resulted in a significantly higher insulinemic index (17). The glycemic index of certain fermented milk products are unknown and the insulinemic indexes of milk products are extremely scarce.

Therefore, the purpose of the present study was to characterize the glycemic and insulinemic responses to milk products and to evaluate the possible influence of the lactic acid in fermented milk. Another objective was to evaluate the acute metabolic effect of fermented milk (yogurt) and pickled cucumber as supplements to a traditional breakfast based on a high–glycemic index bread.

SUBJECTS AND METHODS

Study 1

Test meals: regular and fermented milk products

Besides regular milk, 2 commercial fermented milk products were tested: långfil (ropy milk) and filmjölk. All of the milk products contained 3% fat. The regular milk and filmjölk were produced by Skånemejerier (Malmö, Sweden) and the ropy milk was produced by Arla (Gävle, Sweden). In addition, a lactose solution was included. The lactose solution was prepared from pure lactose (lactose 101394S; BDH, Poole, United Kingdom) and water before every test meal. White-wheat bread (WWB) was used as a reference meal and was prepared according to Liljeberg and Björck (18). The composition of the meals is shown in Table 1.

TABLE 1

Composition of the test meals and the white-wheat bread (WWB) reference meal in study 1

Fermented milk products
WWB Lactose Milk Filmjölk Ropy milk
Total carbohydrate (g) 25 24 25 25 25
Total protein (g) 4.1 17.3 19.2 19.3
Total fat (g) 0.8 15.3 17.4 17.0
Lactic acid (g) 5.2 5.1
Energy
(kJ) 525 408 1300 1413 1399
(kcal) 125 97 309 336 333
Fermented milk products
WWB Lactose Milk Filmjölk Ropy milk
Total carbohydrate (g) 25 24 25 25 25
Total protein (g) 4.1 17.3 19.2 19.3
Total fat (g) 0.8 15.3 17.4 17.0
Lactic acid (g) 5.2 5.1
Energy
(kJ) 525 408 1300 1413 1399
(kcal) 125 97 309 336 333

TABLE 1

Composition of the test meals and the white-wheat bread (WWB) reference meal in study 1

Fermented milk products
WWB Lactose Milk Filmjölk Ropy milk
Total carbohydrate (g) 25 24 25 25 25
Total protein (g) 4.1 17.3 19.2 19.3
Total fat (g) 0.8 15.3 17.4 17.0
Lactic acid (g) 5.2 5.1
Energy
(kJ) 525 408 1300 1413 1399
(kcal) 125 97 309 336 333
Fermented milk products
WWB Lactose Milk Filmjölk Ropy milk
Total carbohydrate (g) 25 24 25 25 25
Total protein (g) 4.1 17.3 19.2 19.3
Total fat (g) 0.8 15.3 17.4 17.0
Lactic acid (g) 5.2 5.1
Energy
(kJ) 525 408 1300 1413 1399
(kcal) 125 97 309 336 333

Chemical analysis

The contents of lactose, glucose, and galactose in the milk products were analyzed by using an enzymatic kit (Boehringer Mannheim, Mannheim, Germany). The lactose content of the regular milk was 4.9% (wet wt) and the fermented milk products contained 3.7% lactose (wet wt). The glucose and galactose contents in all 3 milk products were <0.1 % (wet wt). The starch content of the WWB was analyzed according to Holm et al (19). In addition, the protein (Kjeldahl) and fat (20) contents of the WWB were determined. According to the manufacturer, the lactic acid content of the 2 fermented milk products was 0.8–0.9% (wet wt).

Study design

Ten healthy nonsmoking volunteers (5 men and 5 women aged 28–47 y) with normal body mass indexes (23.4 ± 2.1; in kg/m2) and not receiving drug therapy participated in the study. All of the subjects drank milk regularly and did not experience any discomfort after milk consumption. The test meals, including the reference meal, contained 25 g available carbohydrate; 250 mL water was served with the WWB meal and 150 mL tea or coffee was served with each meal. The subjects were served the test meals in random order on 5 separate occasions at the same time in the morning after an overnight fast. All of the meals were consumed steadily over 12–14 min.

Finger-prick capillary blood samples were taken before the meal (0 min) and 15, 30, 45, 70, 95, and 120 min after the meal for analysis of glucose and at 0, 15, 30, 45, 95, and 120 min for analysis of insulin. Blood glucose concentrations were determined with a glucose oxidase peroxidase reagent and serum insulin concentrations were determined with an enzyme immunoassay kit (Boehringer Mannheim).

The study lasted 3 mo and all of the subjects knew that they could withdraw at any time. The study was approved by the Ethics Committee of the Faculty of Medicine at Lund University.

Study 2

Test meals: WWB with and without fermented and pickled products

The composition of the meals is described in Table 2. The 2 test meals were composed of WWB (with added butter and cheese) and either regular milk (Skånemejerier) and fresh cucumber (WWB + norm) or yogurt (Skånemejerier) and pickled cucumber (WWB + acid) as supplements. Both of the milk products contained 0.5% fat. The reference meal was WWB, which was balanced with butter (80% fat) and cheese (10% fat) to reach the same content of fat and protein as in the 2 test meals. The starch content of the WWB was analyzed according to Holm et al (19), and the carbohydrate content of the milk and yogurt was based on the declaration of contents by the manufacturer. In addition, the protein (Kjeldahl) and fat (20) contents of the WWB were determined. To make 0.5 kg pickled cucumber, 200 mL acetic acid (12%) and 300 mL water were used.

TABLE 2

Composition of the test meals and the white-wheat bread (WWB) reference meal in study 21

1

WWB + norm meal includes WWB + regular milk + fresh cucumber; WWB + acid meal includes WWB + fermented milk (yogurt) + pickled cucumber.

TABLE 2

Composition of the test meals and the white-wheat bread (WWB) reference meal in study 21

1

WWB + norm meal includes WWB + regular milk + fresh cucumber; WWB + acid meal includes WWB + fermented milk (yogurt) + pickled cucumber.

Ten healthy nonsmoking volunteers (3 men and 7 women aged 24–56 y) with normal body mass indexes (21.4 ± 1.9; in kg/m2) and not receiving drug therapy participated in the study. The WWB reference meal was served with 250 mL water, and 150 mL tea or coffee was served with each meal. The subjects were served the test meals in random order on 3 separate occasions at the same time in the morning after an overnight fast. All of the meals were consumed steadily over 12–14 min.

Finger-prick capillary blood samples were taken before the meal (0 min) and 30, 45, 70, 95, 120, and 180 min after the meal for analysis of glucose and at 0, 30, 45, 95, and 120 min for analysis of insulin. Blood glucose concentrations were determined with a glucose oxidase peroxidase reagent and serum insulin concentrations were determined with an enzyme immunoassay kit (Boehringer Mannheim).

The study lasted 3 mo and all of the subjects knew that they could withdraw at any time. The study was approved by the Ethics Committee of the Faculty of Medicine at Lund University.

Calculations and statistical methods

For each subject and type of test meal, the areas under the curves for glucose and insulin were calculated (GRAPHPAD PRISM, version 2.0; Graph Pad Software, San Diego). All areas below baseline were excluded from the calculations. The glycemic and insulinemic indexes were then calculated from the 95-min incremental postprandial blood glucose and insulin areas by using WWB as a reference (glycemic and insulinemic indexes = 100) (1). Statistical analyses were carried out for both indexes and for the mean glucose and insulin concentrations at each time point. Values are presented as means ± SEMs, and all statistical calculations were performed with MINITAB Statistical Software (release 12 for WINDOWS; Minitab, Inc, State College, PA). Significances were evaluated with the general linear model (analysis of variance), followed by Tukey’s multiple comparisons test. Values of P < 0.05 were considered significant.

RESULTS

Study 1: regular and fermented milk products

The blood glucose responses 15 min after the test meals with ropy milk and filmjölk were significantly lower than those after the WWB and the lactose solution, respectively (Figure 1). Between 30 and 70 min after the meal, the glucose response was lower after the lactose solution than after the WWB. From 15 to 45 min after the meal, blood glucose concentrations were significantly lower after the 2 fermented milk meals than after the lactose solution.

FIGURE 1.

Mean (±SEM) incremental blood glucose responses (Δ) in 10 healthy subjects after ingestion of equivalent amounts of carbohydrate from a reference white-wheat bread (▪), a lactose solution (▴), regular milk (♦), and 2 fermented milks: filmjölk (▾) and ropy milk (·). Values with different letters are significantly different, P < 0.05.

FIGURE 1.

Mean (±SEM) incremental blood glucose responses (Δ) in 10 healthy subjects after ingestion of equivalent amounts of carbohydrate from a reference white-wheat bread (▪), a lactose solution (▴), regular milk (♦), and 2 fermented milks: filmjölk (▾) and ropy milk (·). Values with different letters are significantly different, P < 0.05.

The glycemic indexes for all of the milk products were significantly lower than those for both the lactose solution and the WWB (Table 3). However, no differences in glycemix indexes were found between the milk products. The glycemic index was significantly lower after the lactose solution than after the WWB meal.

TABLE 3

Glycemic and insulinemic indexes for the test meals and the white-wheat bread (WWB) reference meal in study 11

Meal Glycemic index Insulinemic index
WWB 100a 100a
Lactose 68 ± 8b 50 ± 6b
Regular milk 30 ± 4c 90 ± 8a
Fermented milk products
Filmjölk 15 ± 3c 98 ± 11a
Ropy milk 15 ± 3c 97 ± 13a
Meal Glycemic index Insulinemic index
WWB 100a 100a
Lactose 68 ± 8b 50 ± 6b
Regular milk 30 ± 4c 90 ± 8a
Fermented milk products
Filmjölk 15 ± 3c 98 ± 11a
Ropy milk 15 ± 3c 97 ± 13a

1

x̄ ± SEM; n = 10. Values within columns with different superscript letters are significantly different, P < 0.05.

TABLE 3

Glycemic and insulinemic indexes for the test meals and the white-wheat bread (WWB) reference meal in study 11

Meal Glycemic index Insulinemic index
WWB 100a 100a
Lactose 68 ± 8b 50 ± 6b
Regular milk 30 ± 4c 90 ± 8a
Fermented milk products
Filmjölk 15 ± 3c 98 ± 11a
Ropy milk 15 ± 3c 97 ± 13a
Meal Glycemic index Insulinemic index
WWB 100a 100a
Lactose 68 ± 8b 50 ± 6b
Regular milk 30 ± 4c 90 ± 8a
Fermented milk products
Filmjölk 15 ± 3c 98 ± 11a
Ropy milk 15 ± 3c 97 ± 13a

1

x̄ ± SEM; n = 10. Values within columns with different superscript letters are significantly different, P < 0.05.

Forty-five minutes postprandially, the regular milk and filmjölk elicited lower insulin responses than did the WWB (Figure 2); 30 and 45 min after the meal, insulin responses were significantly lower with the lactose solution than with the WWB. Insulin concentrations after ropy milk were not significantly different from concentrations after the WWB meal at all time points, except for 95 min postprandially, when insulin responses were significantly lower after the WWB meal. The insulinemic index for the milk products did not differ significantly from those for the WWB but were significantly higher than those for the lactose solution (Table 3). No differences in insulinemic indexes were found between the milk products.

FIGURE 2.

Mean (±SEM) incremental serum insulin responses (Δ) in 10 healthy subjects after ingestion of equivalent amounts of carbohydrate from a reference white-wheat bread (▪), a lactose solution (▴), regular milk (♦), and 2 fermented milks: filmjölk (▾) and ropy milk (·). Values with different letters are significantly different, P < 0.05.

FIGURE 2.

Mean (±SEM) incremental serum insulin responses (Δ) in 10 healthy subjects after ingestion of equivalent amounts of carbohydrate from a reference white-wheat bread (▪), a lactose solution (▴), regular milk (♦), and 2 fermented milks: filmjölk (▾) and ropy milk (·). Values with different letters are significantly different, P < 0.05.

Study 2: WWB with and without fermented and pickled products

The blood glucose response 30 min after the test meals was significantly lower with the WWB + acid meal than with the WWB and WWB + norm meals (Figure 3). At 45 min, the WWB + acid meal produced significantly lower glycemia than did the WWB meal. The glycemic index for the WWB + acid meal was significantly lower than that for the WWB meal (Table 4). At 45 min, the serum insulin response to the WWB + acid meal was significantly lower than the response to the WWB+ norm meal (Figure 4). The insulinemic index for the WWB + acid meal was significantly lower than that for both the WWB and WWB + norm meals (Table 4).

FIGURE 3.

Mean (±SEM) incremental blood glucose responses (Δ) in 10 healthy subjects after ingestion of a reference white-wheat bread meal (WWB; ▪), the WWB meal plus regular milk and fresh cucumber (▴), and the WWB meal plus fermented milk (yogurt) and pickled cucumber (▾). Values with different letters are significantly different, P < 0.05.

FIGURE 3.

Mean (±SEM) incremental blood glucose responses (Δ) in 10 healthy subjects after ingestion of a reference white-wheat bread meal (WWB; ▪), the WWB meal plus regular milk and fresh cucumber (▴), and the WWB meal plus fermented milk (yogurt) and pickled cucumber (▾). Values with different letters are significantly different, P < 0.05.

TABLE 4

Glycemic and insulinemic indexes for the test meals and the white-wheat bread (WWB) reference meal in study 21

Meal Glycemic index Insulinemic index
WWB 100a 100a
WWB + norm 79 ± 10a,b 117 ± 12a
WWB + acid 55 ± 7b 79 ± 11b
Meal Glycemic index Insulinemic index
WWB 100a 100a
WWB + norm 79 ± 10a,b 117 ± 12a
WWB + acid 55 ± 7b 79 ± 11b

1 TABLE 4

Glycemic and insulinemic indexes for the test meals and the white-wheat bread (WWB) reference meal in study 21

Meal Glycemic index Insulinemic index
WWB 100a 100a
WWB + norm 79 ± 10a,b 117 ± 12a
WWB + acid 55 ± 7b 79 ± 11b
Meal Glycemic index Insulinemic index
WWB 100a 100a
WWB + norm 79 ± 10a,b 117 ± 12a
WWB + acid 55 ± 7b 79 ± 11b

1 FIGURE 4.

Mean (±SEM) incremental serum insulin responses (Δ) in 10 healthy subjects after ingestion of a reference white-wheat bread meal (WWB; ▪), the WWB meal plus regular milk and fresh cucumber (▴), and the WWB meal plus fermented milk (yogurt) and pickled cucumber (▾). Values with different letters are significantly different, P < 0.05.

FIGURE 4.

Mean (±SEM) incremental serum insulin responses (Δ) in 10 healthy subjects after ingestion of a reference white-wheat bread meal (WWB; ▪), the WWB meal plus regular milk and fresh cucumber (▴), and the WWB meal plus fermented milk (yogurt) and pickled cucumber (▾). Values with different letters are significantly different, P < 0.05.

DISCUSSION

Milk products are an important component of Scandinavian breakfasts and are generally regarded as having low glycemic indexes (21). In the present study, the low glycemic indexes of milk products were confirmed and ranged from 15 to 30. The presence of lactic acid in the fermented milk products filmjölk and ropy milk did not significantly affect glycemia, possibly because of the remarkably low incremental glycemic areas seen with all of the milk products.

In contrast with the findings for the comparison between regular and fermented milk products, there was a slight difference in glycemic index between the WWB + norm meal and the WWB + acid meal (study 2). In the WWB + acid meal, both the fermented milk (yogurt) and the pickled cucumber contained organic acids. Because the fermented milk products in study 1 did not have any significant effect on the insulin responses, it seems reasonable that the acetic acid in the pickled cucumber was mainly responsible for the insulin-lowering effect. This finding agrees with earlier findings that acetic acid lowers postprandial glycemia by reducing the gastric emptying rate (16).

The milk products and the cucumber were served in addition to the white bread; thus, the WWB + norm and WWB + acid meals contained a higher amount of carbohydrates (60–64 g) than did the WWB meal (50 g). Despite this amount, both meals with milk products produced a lower glycemic index than did the WWB meal.

Foods for which glycemic indexes have been published, in contrast with milk, are comparatively rich in carbohydrates. Most information regarding starchy foods is readily available, and for this group of products the literature indicates a linear correlation between glycemic indexes and insulinemic indexes (6), suggesting that low–glycemic index foods are also less insulin demanding. The present study with milk and meals with added milk clearly showed that this linear correlation does not apply to all low–glycemic index foods.

Obviously, fermented and nonfermented milk products give rise to insulinemic responses far exceeding what could be expected from their low glycemic indexes. In fact, insulinemic indexes for the milk products tested were not significantly different from those for the WWB meal. All of the milk products included in study 1 induced postprandial hypoglycemia after <50 min postprandially, which may be explained by the high insulin concentrations. Given the hypothesis that insulinemia is a modulator of insulin resistance, this is an important finding. The fact that insulinemia was greater after the milk products than after an equivalent amount of lactose indicates that some milk component in addition to lactose can stimulate insulin secretion. This finding implies that milk may in fact produce higher glycemic indexes when tested in individuals with diminished (type 2 diabetic subjects) or absent (ie, type 1 diabetic subjects) β cell function than in healthy subjects capable of responding to the insulinotropic components in milk.

It is important to note that the subjects who participated in the studies did not have any history of lactose malabsorption. Because lactase persistence varies between populations, the glycemic response to lactose in milk may vary.

The glycemic index tended to decrease and the insulinemic index tended to increase when the WWB meal was consumed with regular milk, although not significantly so. This finding supports an insulinotropic effect of milk. Interestingly, consumption of fermented milk (yogurt) and pickled cucumber significantly lowered both the glycemic and insulinemic response to the WWB meal, suggesting a favorable effect of organic acids.

In the mid-1980s, Gannon et al (22) found milk to be a potent insulin secretagogue in type 2 diabetic patients. Some years later, Schrezenmeir et al (23) reported that the postprandial glucose and insulin responses to a milk-containing breakfast did not correlate in healthy individuals. A possible explanation for an insulinotropic effect of milk involves amino acids and lipids, because it is known that these components can increase the insulin secretion or the insulin demand of a meal (24–26).

As judged from the results of the present study, the time has come to acknowledge the insulinotropic properties of milk. An interesting objective of future research is to evaluate the metabolic effect of milk in a mixed diet and to identify the secretagogue involved.

1 Jenkins DJA , Wolever TMS , Taylor RH , et al. Glycemic index of foods: a physiological basis for carbohydrate exchange. Am J Clin Nutr 1981;34:362–6. 2 Järvi AE , Karlström BE , Granfeldt YE , Björck IME , Asp N-G , Vessby BOH . Improved glycemic control and lipid profile and normalized fibrinolytic activity on a low-glycemic index diet in type 2 diabetic patients. Diabetes Care 1999;22:10–8. 3 Salmerón J , Ascherio A , Rimm EB , et al. Dietary fibre, glycemic load, and risk of NIDDM in men. Diabetes Care 1997;20:545–50. 4 Salmerón J , Manson JE , Stampfer MJ , Colditz GA , Wing AL , Willett WC . Dietary fibre, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women. JAMA 1997;277:472–7. 5 Frost G , Leeds AA , Doré CJ , Madeiros S , Brading S , Dornhorst A . Glycaemic index as a determinant of serum HDL-cholesterol concentration. Lancet 1999;353:1045–8. 6 Björck IME , Liljeberg HGM , Östman EM . Low glycaemic-index foods. Br J Nutr 2000;83(suppl):S149–55. 7 DeFronzo RA , Ferrannini E . Insulin resistance. A multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidemia, and atherosclerotic cardiovascular disease. Diabetes Care 1991;14: 173–94. 8 FAO/WHO. Carbohydrates in human nutrition: report of a joint FAO/WHO expert consultation. FAO Food Nutr Pap 1998;66:1–140. 9 Granfeldt YE , Björck IME . Glycemic response to starch in pasta: a study of mechanism of limited enzyme availability. J Cereal Sci 1991;14:47–61. 10 Tovar J , Granfeldt YE , Björck IME . Effects of processing on blood glucose and insulin responses to starch in legumes. J Agric Food Chem 1992;40:1846–51. 11 Granfeldt YE , Liljeberg HGM , Drews A , Newman R , Björck IME . Glucose and insulin responses to barley products: influence of food structure and amylose-amylopectin ratio. Am J Clin Nutr 1994;59: 1075–82. 12 Jenkins DJA , Wolever TMS , Jenkins AL . Starchy foods and glycemic index. Diabetes Care 1988;11:149–59. 13 Liljeberg HGM , Granfeldt YE , Björck IME . Metabolic response to starch in bread containing intact kernels versus milled flour. Eur J Clin Nutr 1992;46:561–75. 14 Liljeberg HGM , Lönner CH , Björck IME . Sourdough fermentation or addition of organic acids or corresponding salts to bread improves nutritional properties of starch in healthy humans. J Nutr 1995;125:1503–11. 15 Liljeberg HGM , Björck IME . Delayed gastric emptying rate as a potential mechanism for lowered glycemia after eating sourdough bread: studies in humans and rats using test products with added organic acids or an organic salt. Am J Clin Nutr 1996;64:883–93. 16 Liljeberg HGM , Björck IME . Delayed gastric emptying rate may explain improved glycaemia in healthy subjects to a starchy meal with added vinegar. Eur J Clin Nutr 1998;52:368–71. 17 Liljeberg HGM , Granfeldt YE , Björck IME . Products based on a high fiber barley genotype, but not on common barley or oats, lower postprandial glucose and insulin responses in healthy humans. J Nutr 1996;126:458–66. 18 Liljeberg HGM , Björck IME . Bioavailability of starch in bread products. Postprandial glucose and insulin responses in healthy subjects and in vitro resistant starch content. Eur J Clin Nutr 1994;48: 151–63. 19 Holm J , Björck IME , Drews A , Asp N-G . A rapid method for the analysis of starch. Starch/Stärke 1986;38:224–6. 20 Lange HJ . Fettbestimmung. (Fat analysis.) In: Lange HJ . ed. Untersuchungsmethoden in der Konservenindustrie. (Analysis methods in the canning industry.) Berlin: Paul Parey, 1972:211–13 (in German). 21 Foster-Powell K , Miller JB . International tables of glycemic index. Am J Clin Nutr 1995;62(suppl):871S–90S. 22 Gannon MC , Nuttall FQ , Krezowski PA , Billington CJ , Parker S . The serum insulin and plasma glucose responses to milk and fruit products in type 2 (non-insulin-dependent) diabetic patients. Diabetologia 1986;29:784–91. 23 Schrezenmeir J , Tato F , Tato S , et al. Comparison of glycemic response and insulin requirements after mixed meals of equal carbohydrate content in healthy, type-1, and type-2 diabetic man. Klin Wochenschr 1989;67:985–94. 24 Schmid R , Schusdziarra V , Schulte-Frohlinde E , Maier V , Classen M . Role of amino acids in stimulation of postprandial insulin, glucagon, and pancreatic polypeptide in humans. Pancreas 1989;4: 305–14. 25 Pedersen A , Marckmann P , Sandström B . Postprandial lipoprotein, glucose and insulin response after two consecutive meals containing rapeseed oil, sunflower oil or palm oil with or without glucose at the first meal. Br J Nutr 1999;82:97–104. 26 Joannic J-L , Auboiron S , Raison J , Basdevant A , Bornet F , Guy-Grand B . How the degree of unsaturation of dietary fatty acids influence the glucose and insulin responses to different carbohydrates in mixed meals. Am J Clin Nutr 1997;65:1427–33.

FOOTNOTES

2 Supported by grants from the Swedish Council for Forestry and Agricultural Research (project 500615/96) and the Swedish Dairy Association. © 2001 American Society for Clinical Nutrition

Glycemic Load Chart

Glycemic load chart below should be used as a guide to make wiser food choices to perform better all day long and feel better generally by keeping your blood glucose levels relatively constant.

If there is a sudden spike in your blood sugar, your pancreas secretes more insulin, bringing your blood sugar down by transforming the excess sugar to fat. The higher the rate is, the lower your blood sugar will go. Blood glucose being too low means increased hunger and fatigue.

Glycemic index and glycemic load are both about the impact of carbohydrate rich foods on your blood glucose levels or in other words how quick or slow they cause a rise and a fall.

The difference is that glyemic load is based on the idea that a small serving of a high GI food will have the same kind of effect as a big serving of a low GI food. Foods that are mostly water, for instance, will not cause a sudden rise in your blood sugar even if they have high GI values.

That’s how they’ve come up with the glycemic load- GL. GL takes into account both the GI value and the quantity of carbohydrate in that food. So it provides a more accurate picture than glycemic index, as you will see on the glycemic load chart below.

Glycemic Load = (Quantity of carbohydrate content x GI ) / 100.

• GL of 20 or more is high, a GL of 11 to 19 is medium and a GL of 10 or less is low.

• A food with a GI of 70 and a carb content of 10g has a GL value of 7.

• A food with a GI of 10 and a carb content of 70g has also a GL value of 7.

Glycemic Load Chart:

Dairy Products:

• Full cream milk — 250ml — 3

• Soy milk — 250ml — 4

• Skimmed milk 250ml — 4

• Semi skimmed milk — 250ml — 4

• Low fat ice cream — 50g — 6

• Low fat fruit yogurt — 200g — 7

• Banana smoothie — 250ml — 8

• Mars flavoured milk — 250ml — 15

Fruits:

• Grapefruit — 120g — 3

• Cherries — 120g — 3

• Peach — 120g — 4

• Watermelon —120g — 4

• Pear — 120g — 5

• Plum — 120g — 5

• Orange — 120g — 5

• Apricot — 120g — 5

• Apple — 120g — 6

• Grapes — 120g — 8

• Banana — 120g — 12

• Sultanas — 60g — 25

• Raisins — 60g — 28

Vegetables:

• Broccoli — 80g — 1

• Cabbage — 80g — 1

• Spinach — 80g — 1

• Asparagus — 80g — 1

• Carrot — 80g — 3

• Green peas — 80g — 3

• Broad beans — 80g — 9

• Parsnips — 80g — 12

• Sweet potato — 150g — 17

• Sweet corn — 150g — 17

• Baked potatoes — 150g — 26

Legumes:

• Soy beans — 150g — 1

• Lentils — 150g — 5

• Split peas — 150g — 6

• Baked beans — 150g — 7

• Red kidney beans — 150g — 7

• Garbanzos — 150g — 8

• Romano beans — 150g — 8

• Pinto beans — 150g — 10

• Navy beans — 150g — 12

Grains:

• Barley — 150g — 11

• Bulgur — 150g — 12

• Whole wheat kernels — 50g — 14

• Brown rice — 150g — 18

• Couscous — 150g — 23

• White rice — 150g — 23

Cereals:

• Muesli — 30g — 10

• Porridge — 250g — 12

• Kellogg’s All Bran — 30g — 12

• Swiss muesli — 30g — 13

• Oatmeal — 250g — 13

• Kellogg’s Special K — 30g — 14

• Puffed wheat — 30g — 16

• Instant oatmeal — 250g — 17

• Corn flakes — 30g — 19

• Coco pops — 30g — 20

Breads:

• Burgen fruit loaf — 30g — 6

• Pumpernickel Bread — 30g — 6

• Barley and sunflower bread — 30g — 6

• Rye bread — 30g — 7

• Rice bread — 30g — 8

• Whole wheat bread — 30g — 9

• White pita bread — 30g — 10

• Baguette — 30g — 10

• White bagel — 30g — 11

Snacks and Beverages:

• Tomato juice — 250ml — 2

• Apple juice — 250ml — 10

• Carrot juice — 250ml — 10

• Banana cake — 80g — 12

• Vanilla wafers — 25g — 14

• Corn tortilla — 60g — 14

• Pepsi — 250ml — 15

• Cranberry juice drink — 250ml — 16

• Sponge cake — 60g — 16

• Rice cakes — 25g — 17

• Snickers bar — 60g — 19

• Fanta — 250ml — 23
*Foods with low GL values are almost always low in glycemic index too. Those with medium or high GL could be anything- from very low to very high GI.

*You can only see the glycemic load values of foods on the Glycemic Load Chart above, if you would like the glycemic index values as well, please refer to the Glycemic Index Chart, where you can make a comparison between glycemic index and glycemic load values of carbohydrate rich foods.

Return from Glycemic Load Chart to Glycemic Index home page

Or take me to Low Glycemic Food List from Glycemic Load Chart

Glycemic index whole milk

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