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A glass of cow's milkThe Miracle of Milk:

Is There a Link Between

High-Dairy Diets and Weight Loss?

 

 

 

 

By Caroline Elizabeth Jones

 

 

 

 

 

 

 

 

Introduction

Obesity has become an American epidemic, but obesity has not become a problem because people do not want to be healthy. Many fad diets, pills, and unorthodox practices that promise weight loss suggest that the yearning to lose weight is at an all-time high. Perhaps the real culprit behind obesity is the change in the American lifestyle. Just as children have swapped their baseball mitts for video games, and fast food has replaced family dinners, a canned soda has oftentimes taken the place of a glass of milk. As milk consumption has decreased over the years, the prevalence of obesity has skyrocketed. Would an increase in milk consumption therefore help reverse the obesity trend? Is this a safe correlation to make? The dairy industry would like you to believe it is, and many companies today promote their dairy products as part of a weight loss program.

 

The Claims

According to the 2424milk campaign, drinking 24 ounces of low-fat or fat free milk each day can help you lose more weight than a low-dairy diet with the same amount of calories. The claim is that the calcium and protein found in milk aids in the body’s fat burning mechanisms, particularly helping the individual burn fat around his or her mid-section, while still preserving muscle mass (www.2424milk.com).

 

Recently, the dairy industry has initiated what it calls “The Great American Weight Loss Challenge.” It documents many success stories where women have experienced moderate weight loss, each prefaced with “results not typical.” For example, Marilyn Harris attributes her 25 pound weight loss to her low-calorie, high-dairy diet (www.2424milk.com).

 

In addition, Yoplait claims that according to its studies, eating 3 servings of Yoplait Light each day in accord with a high-calcium, low-calorie diet will increase both weight and fat loss. The company claims its findings show that people who ate Yoplait Light yogurt, on average, lost 22% more weight than those who consumed the same amount of calories but whose diet lacked calcium. Remarkably, the high-dairy dieters lost 61% more total fat, including 81% more fat from around their middle (http://www.yoplait.com/health_weightloss.aspx).

 

Like milk’s “Great American Weight Loss Challenge”, Yoplait has launched its own weight-loss program called “So Good Girls”, where one can go online and track the progress of six women as they lose weight and maintain healthier lifestyles on an eight-week long program. The program consists of low-calorie high-calcium dieting, including 3 servings of Yoplait yogurt each day (http://sogoodgirls.com/).

 

The Rationale

The 2424milk campaign references Michael Zemel, PhD, a professor of medicine and nutrition at the University of Tennessee, who maintains that milk can be a successful dieting tool. He argues that a low-dairy diet initiates a defense mechanism in the body, where a hormonal response begins to preserve any and all available calcium by decreasing the speed at which fat is broken down. His rationale is based on the idea that by adding more calcium to one’s diet, one is helping himself burn more fat. Furthermore, he argues that his research reveals that calcium is nearly two times more effective than calcium pills, but admits he has no explanation for this result except the theory that the various other nutrients in milk cooperate to trigger fat burning (www.2424milk.com).

 

In addition to referencing Zemel’s arguments, the 2424milk campaign introduces Pam Peeke MD. According to her, milk’s nutrient combination seems to aid in breaking down fat in the body’s fat cells. In keeping with Zemel, Peeke points to milk’s ability to control a hormone, which is involved in fat storage and break down. In a low-calcium diet, fat cells are signaled to preserve fat (www.2424milk.com).

 

The National Dairy Council maintains the same claims as the 2424milk campaign but admits that they have yet to reach a full understanding between dairy and weight loss. Again, they turn to Dr. Michael Zemel, whose research points to a fat-burning mechanism at the cellular level. In addition, however, they consult Dr. Ed Melanson and his fat oxidation studies, which appear to reveal that a low-calorie, high-dairy diet increases fat oxidation (http://www.nationaldairycouncil.org).  

 

 

 

The Evidence

The Science Behind the Claims

It is relatively simple to find evidence supporting these claims, but there also exists some research that disputes it. The dairy industry has launched several randomized clinical trials and observational studies throughout the United States and has looked at many of the experiments conducted in Denmark, Italy, and Greece (www.2424milk.com).

 

In a 2005 article in The New York Times entitled “All That Calcium and Maybe Weight Control Too,” Jane Brody outlined a brief history of some relatively new experiments. Over twenty years ago, the National Health and Nutrition Examination Survey concluded that there appeared to be a significant correlation between low calcium consumption and obesity. Since then, the Heritage Family Study, which was conducted at six various medical centers on 362 men and 462 women, showed that low calcium intake could be associated with higher body fat percentages, particularly torso body fat, and especially in men and white women (Brody, 2005).

 

Clinical Trials

Many randomized clinical trials followed overweight and obese adults as they embarked on low-calorie, high-dairy diets, in which they ate or drank 3 servings of milk, yogurt, or cheese each day. The results often, but not always, indicated that those who only reduced the amount of calories lost less weight than those who also increased their dairy intake (www.2424milk.com).

 

Zemel Confirms the Mechanism

In a 2002 study on agouti transgenic mice, Zemel determined the mechanisms and implications by which calcium seems to regulate obesity. According to his research, high-calcium diets minimize weight gain during times of over-consumption and increase lipolysis during times of low caloric intake, so that the individual loses weight. The way that this occurs is that as calcium increases in the cell, it speeds up lipogenic gene expression, lipogenesis, and adiposity. Conversely, in low-calcium diets, calcium influx is stimulated to increase adiposity. These results were supported by other epidemiological and clinical data that showed that an increase in calcium intake reduced the chance of becoming obese. Furthermore, Zemel concluded that the calcium in milk is better at preventing obesity than calcium supplements possibly because of milk’s bioactive compounds, including its angiotensin converting enzyme inhibitor (Zemel, 2002).

 

High-Dairy Diets Increase Weight and Fat Loss

In a twenty four-week long randomized, placebo-controlled trial, Zemel monitored the diet and weight loss of 32 obese adults. Each person lowered his or her daily caloric intake by 500 kcal. The standard diet group included 400-500 mg of calcium and a supplemental placebo in their diet. The high-calcium group included 800 mg of supplemented calcium. The high-dairy diet group consumed 1200 to 1300 mg of calcium from their diet and were also supplemented with a placebo. Zemel’s results showed that those on the standard diet lost an average of 6.4% of their body weight. Those on the high-calcium diet lost 26% more weight and 38% more fat (50.1% of the total fat was lost from the trunk region). Those on the high-dairy diet lost 70% more weight and 64% more total fat (66.2% fat lost from trunk region) (Zemel, 2004).

 

High-Calcium Diets Reduce Weight Gain When Refeeding

In a study aimed at determining how dairy affected energy partitioning, obesity was brought about in aP2-agouti transgenic mice via a high-sucrose/high-fat diet, proceeded by fat loss, which was induced by restricting calories via a high-calcium diet. After six weeks, some mice were given a low-calcium diet (0.4%), while some were given a high-calcium diet (1.3%). The results showed that the low-calcium diet caused both weight and fat regain, but the mice on the high-calcium diet only gained 45% of their fat back. They also showed that the high-calcium diet yielded a significant increase in lipolysis and a decrease in expression of fatty acid synthase. In all, high-calcium diets seem to reduce weight gain when refeeding (Sun X, 2004).

 

Calcium and Weigh Loss in African-Americans

Two randomized trial were conducted. One monitored 34 obese African-Americans for 24 weeks, and he other followed 29 obese African-Americans under similar conditions. Both trials split the participants into two groups, in which one underwent a low-dairy diet and one underwent a high-dairy diet. In the first study, the high dairy dieters lost more body fat, trunk fat, insulin, and blood pressure; they also increased their lean mass. The second trial showed similar results (Zemel, 2005).

Calcium and Weight Loss in Children

In a study on Asian and Caucasian girls between the ages of 9 and 14, dietary calcium could be linked to a decrease in body fat (Novotny, 2004). However, in a clinical trial that followed 192 healthy-weight girls aged 8 to 12 years old for 10 years, there seemed to be no connection between high levels of calcium intake and a decrease in BMI or body fat (Phillips, 2003).

 

When Calcium Does Not Stimulate Weight Loss

However, not all experiments showed a direct link between dietary calcium and weight loss. For example, a 12 month study of 155 normal-weight women between 18 and 30 years of age showed no apparent effect of dairy on body weight or fat mass (Gunther, 2005).

 

Observational Studies

In addition to controlled clinical trials, observational studies were launched to look at the role of dairy in weight loss throughout various populations and confirmed that a high-dairy diet consisting of 3 to 4 servings a day led to increased weight loss. While such studies do not verify diet as the cause to the effect of weight loss, they do set guidelines for future research (www.2424milk.com).

 

For instance, a 10-year prospective study known as the CARDIA study, observed 3,000 adults between the ages 18 and 30. It appeared that high-calcium consumption protected those who were overweight from becoming obese (Pereira, 2002). 

 

Can It Be As Good As It Seems?

The dairy industry is ultimately responsible for presenting this information and for making all the evidence available. It runs the ads and displays the success stories in an effort to help control America’s obesity epidemic. However, the dairy industry might be presenting this information for its own profit as well. By marketing its products as part of a weight loss program and establishing its very own program, it is essentially promoting the sales of milk, yogurt, and cheese products. While many of these research projects have been financed by government grants, many were also done by the very dairy industry. Therefore, one must question the results with the possibility of bias. Nevertheless, on the whole the evidence seems fair and objective.

 

Conclusion

It still seems uncertain whether consuming a high-calcium, low-calorie diet will help an overweight or obese person lose more weight and burn more fat than a simple low-calorie diet. However, the evidence does seem to suggest that there is a link between dairy and weight loss and fat reduction. In addition, calcium is necessary for bone growth and various other process that help maintain a healthy body. Therefore, including it moderately in one’s diet would be beneficial regardless if it induces weight loss or not.

 

Works Cited

“24/24 Milk Your Diet. Lose Weight”. 12 September 2006. <http://www.2424milk.com>

 

Brody, Jane E. “All That Calcium, and Maybe Weight Control Too.” The New York

            Times. 14 June 2005.

 

Gunther, C.W. (2005). Dairy Products Do Not Lead to Alterations in Body Weight and

Fat Mass in Young Women in One Year Intervention. American Journal of Nutrition, 81(4): 751-6.

 

“National Dairy Council.” 12 September 2006. < http://www.nationaldairycouncil.org>

 

Novotny R, Daida YG, Acharya S, Grove JS, Vogt TM (2004). Dairy intake is associated

with lower body fat and soda intake with greater weight in adolescent girls. Journal of Nutrition, 134(8): 1905-1909.

 

Pereira (2002). Dairy Consumption, Obesity, and the Insulin Resistance Syndrome in

            Young Adults. Journal of the American Medical Association, (282: 2081-2089).

 

Phillips SM, Bandini LG, Cyr H, Cloclough-Douglas S, Naumova E, Must A. (2003).

            Dairy food consumption and body weight and fatness studied longitudinally over

            The adolescent period. International Journal of Obesity. 2003; 27-1106-13.

 

Sun X, Zemel, M.B. (2004). Calcium and Dairy Products Inhibit Weight and Fat Regain

            During Ad Libitum Consumption Following Energy Restriction in Ap2-agouti

            Transgenic Mice. J Nutrition, 134(11):3054-60.

 

“Yoplait.” 18 September 2006. <http://www.yoplait.com/health_ weightloss.aspx>

 

“Yoplait: So Good Girls.” 18 September 2006. < http://www.sogoodgirls.com/>

 

Zemel, M.B. (2002). Regulation of Adiposity and Obesity Risk by Dietary Calcium:

Mechanisms and Implications. J Am Coll Nutrition. 21(2): 146S-151(S).

 

Zemel, M.B., Thompson, W., Milstead, A., Morris, K., Campbell, P. (2004). Calcium

and Dairy Acceleration of Weight and Fat Loss During Energy Restriction in Obese Adults. Obesity Research, 12:582-590.

 

Zemel, M.B., Richards, J., Milstead, A., Campbell, Peter. (2005). Effects of Calcium and

Dairy on Body Composition and Weight Loss in African-American Adults. Obesity Research. 13:1218-1225.

 

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