McDougall weighs in on the 2010 Dietary Guidelines Advisory Committee: “Except for a few hopeful sentences, the committee presents a report filled with fear mongering, doubletalk, omissions of major topics, consistently biased views of the scientific literature, and inexcusable factual errors that favor the livestock industries.”

Lack of physical activity is not the cause of weight gain in children, according to a study in Archives of Diseases in Childhood. Researchers measured physical activity and body fat percentage in 202 children annually from age 7 to age 10. The amount of physical activity did not result in changes in body fat. Although physical activity is important, the researchers concluded that focusing on food intake may have a larger impact on weight loss.

Metcalf BS, Hosking J, Jeffery AN, Voss LD, Henley W, Wilkin TJ. Fatness leads to inactivity, but inactivity does not lead to fatness: a longitudinal study in children (EarlyBird 45). Arch Dis Child. Published ahead of print June 23, 2010. doi: 10.1136/adc.2009.175927.

Dr. McDougall challenges claims by Dr. Andrew Weil in a recent Huffington Post article: “Pointing the guilty finger away from fat and towards carbohydrates is self-serving for those diet-experts who themselves refuse to give up their high-fat diet. Food industries buy scientific research published in respectable journals because it is one of their most effective marketing tools.”

People with diabetes have up to twice the risk of developing liver, pancreatic, and endometrial cancers, compared to the risk for people who do not have diabetes, according to a study published in CA: A Cancer Journal for Clinicians. Cancers of the colon, rectum, bladder, and breast are also more common among people with diabetes. The reason for the increased risk is unknown but may be due to similar risk factors for both diseases, such as obesity and older age. However, the link may also be from diabetic complications like high blood sugar, high blood insulin, inflammation, or altered hormone regulation, all having the potential to increase cancer risk. This report from the American Diabetes Association and the American Cancer Society suggests that a high intake of whole grains, fruits, and vegetables, and low intake of processed and red meats are associated with lower cancer risk.

Giovannucci E, Harlan DM, Archer MC, et al. Diabetes and Cancer: A Consensus Report. CA Cancer J Clin. Published ahead of print June 16, 2010. doi: 10.3322/caac.20078.

Meat eating leads to weight gain, according to a new study published in the American Journal of Clinical Nutrition. Researchers studied the diets of 373,803 participants in the European Prospective Investigation into Cancer (EPIC study). Those who ate 8.8 ounces (about two servings) of meat per day gained more weight year by year, compared with people who ate less meat (or none at all). The weight gain attributable to meat consumption was about 1 extra pound per year. The researchers concluded that reducing meat consumption may help people avoid weight gain.

Vergnaud AC, Norat T, Romaguera D, et al. Meat consumption and prospective weight change in participants of the EPIC-PANACEA study. Am J Clin Nutr. Published ahead of print June 30, 2010. doi: 10.3945/ajcn.2009.28713.

Vegetarians have lower instances of depression, according to a new study in Nutrition Journal. Researchers looked at 60 vegetarians and 78 meat-eaters in the southwestern United States and found that vegetarians scored significantly better on standardized mood tests. The mood tests measured depression, anxiety, and stress and were compared to food frequency questionnaires. The vegetarians consumed less eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid—all animal sources of omega-6 fatty acids—but reported higher mean intakes of plant sources of omega-6 and omega-3.

Beezhold BL, Johnston CS, Daigle DR. Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults. Nutr J. 2010;9:26.