Thursday, March 22, 2007

Lose Weight by Eating More Dairy?...Maybe Not So Fast

Dairy Diet Myth

You’ve probably seen the ads in magazines or on TV. “Milk, cheese-
yogurt. Burn more fat, lose weight.” Drink 24 ounces
of milk every 24 hours and that skinny hourglass figure will be
yours. Eat three servings of yogurt every day and squeeze into
that itsy-bitsy bikini...

Beginning October 2003 "Drink Milk... Lose Weight" ads ran in over 30 newspapers and magazines when the dairy industry launched an entire "Healthy Weight with Milk" campaign to boost sales. Curiously, that also happened to be the same year a review of that exact subject was published in the Journal of Nutrition. The review found nine randomized controlled studies in the medical literature on body weight and dairy. Seven of the nine studies found no significant change in body weight compared to controls and the last two found that those who increased their dairy consumption gained significantly more weight than the nondairy control groups.[1] Subsequent and even larger studies published in 2004[2] and 2005[3] showed the exact same thing.

So, wait a second. How can the dairy industry's ads claim that "a clinical study shows it helps you burn more fat and lose more weight than just cutting calories alone?" Well, because there are actually three small published studies that found greater weight loss in people who were told to cut calories and eat dairy foods and all were done by one researcher with a patent on the claim. Michael Zemel of the University of Tennessee, found that study participants instructed to eat more dairy did seem to lose more weight. Yes, of course the studies were bought and paid for by the dairy industry, but it goes further than that. This guy Zemel owns a patent on the claim that dairy foods aid weight loss, which is licensed to dairy food manufacturers. As the Center for Science in the Public Interest noted, "In the world of patents and PR, a little science can go a long way."[4] For an in depth analysis of Zemels work and how it is assisting the Dairy Industry check out the Nutrition Action Health Letter Spetember 2005 available online at

Similar maneuverings were involved in the increased dairy recommendation in the new USDA Dietary Guidelines, even though a recent World Health Organization review found no significant relationship at all between low dairy consumption and osteoporotic fracture risk.[5] Assigned to write the dairy guideline was Connie Weaver, head of nutrition at Purdue University and a funding favorite of the National Dairy Council. Walter Willet, head of nutrition at Harvard, calls the guideline committee's report "egregious," accusing them of ignoring the evidence linking dairy to cancer. "There is no nutritional requirement for dairy," Dr. Willet told the Wall Street Journal, "at all."[6]
To hopefully clear up the dairy/weight question once and for all, on June 6, 2005, Harvard researchers published what may be considered the definitive study on the subject in the Archives of Pediatrics and Adolescent Medicine. A study which followed the milk-drinking habits of not 11 kids, or even 12 kids, but over 12,000 kids! After following these 9- though 14-year-olds for years, they found that "children who reported higher total milk intake experienced larger weight gains." The more milk they drank, the heavier they became. Boys who drank the "recommended" three servings of milk a day were 35% more likely to become overweight and girls who drank three servings were 36% more likely to become overweight over time.[7]
"Given the high prevalence of lactose intolerance, the energy content and saturated fat in milk, and evidence that dairy products may promote both male (prostate) and female (ovarian) cancers, we should not assume that high intakes [of dairy] are beneficial," the researchers told reporters. "Furthermore, these cancers may be linked to consumption during adolescence."[8]
What most surprised the researchers was that those who drank low-fat milk (skim and 1%) gained the most weight of all! The weight gain seemed tied more to the dairy protein intake than the dairy fat intake (extra whey protein is often added to low-fat milk during processing). Although there are at least four human studies that show that the dairy protein whey itself may promote weight gain, the researchers guessed that the blame lay in the growth hormones in milk, like the sex steroid estrone found in whey. After all, milk is designed by mother nature to start an 80-pound calf on her way to 1,400 pounds by her second birthday.
This new study has serious implications for our childhood obesity epidemic, which not only has devastating health consequences but social consequences as well. A study released the same week by researchers at the Centers for Disease Control found that teens who perceived themselves as overweight were more than twice as likely to attempt suicide.[9]

[1] Barr SI. "Increased Dairy Product or Calcium Intake: Is Body Weight or Composition Affected in Humans?" Journal of Nutrition 133(2003):245-8S.
[2] Obesity Research 12(2004):A23.
[3] Gunther CW, Legowski PA, Lyle RM, et al. "Dairy Products Do Not Lead to Alterations in Body Weight or Fat Mass in Young Women In A 1-Y Intervention." Am J Clin Nutr 2005;81:751-6.
[4] "Dairy Does Diets." Nutrition Action Healthletter September 2004:8.
[5] Kanis JA, et al."A Meta-Analysis of Milk Intake and Fracture Risk: Low Utility For Case Finding." Osteoporisis International 21 October 2004.
[6] Zamiska N. "How Milk Got a Major Boost By Food Panel." Wall Street Journal 30 August 2004:B1.
[7] Berkey CS, et al. "Milk, Dairy Fat, Dietary Calcium, and Weight Gain ." Archives of Pediatrics and Adolescent Medicine 1599(2005):543-50.
[8] Fox M. "Milk may make for heavier kids, study finds." Reuters 6 June 2005.
[9] Eaton DK, et al. "Associations of Body Mass Index and Perceived Weight With Suicide Ideation and Suicide Attempts Among US High School Students." Archives of Pediatrics and Adolescent Medicine 1599(2005):513-9.

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