Three daily servings of reduced-fat milk: An evidence-based recommendation?

Ludwig, D.S. and Willett, W.C. JAMA Ped, July 2013.

The American Academy of Pediatrics and the American Heart Association recommend that children drink skim or low-fat milk after age 2. In an editorial in JAMA Pediatrics, Drs. David Ludwig and Walter Willett argue that there is actually little data to support the idea that skim and low-fat milk lead to better health outcomes than whole milk.

A link between FTO, ghrelin and impaired brain food-cue responsivity

Efthimia, K., et al. J. Clin Invest, July 2013.

Mutations in the fat mass and obesity gene (FTO) are associated with human obesity and obesity-prone behaviors and are present in about one in six adults. Having two copies (homozygous) of the high-risk allele is associated with a 70 percent higher likelihood of becoming obese than those with low-risk alleles, but the reason why has remained elusive. A recent study showed people with this gene had greater activation of brain regions that regulate appetite, reward processing and incentive motivation when they were shown pictures of fatty foods, making them look more tempting. People with this high-risk allele also had altered levels of the hunger hormone ghrelin, which is a key mediator of eating behavior. 

Bioelectrical impedance analysis to estimate body composition in children and adolescents: A systematic review and evidence appraisal of validity, responsiveness, reliability and measurement error

Talma H,, et al. Obes Rev. July 2013.
Many clinicians use bioelectrical impedance analysis (BIA) to measure body fat in their patients affected by overweight and obesity, as it is a practical and relatively inexpensive method for determining percent of body fat. The reliability, validity, responsiveness and measurement error of BIA was compared to gold standards [dual-energy X-ray absorptiometry (DEXA), isotope dilution (e.g. deuterium ¹⁸O)] and underwater weighing (UWW)) in children and adolescents in a systematic literature search. The authors found that there were considerable differences between BIA and gold standards for measures of body composition (both negative and positive), which suggests that there is little evidence for validity of BIA. There was strong evidence for good reliability; however, test-retest means differences ranged from 7.5 percent to 13.4 percent of total percent of body fat, indicating considerable measurement error. This review suggests that although BIA may be a practical method to estimate percent of body fat in children and adolescents, validity and measurement error are not acceptable.