There are many different explanations for the global obesity epidemic, but here’s one I hadn’t come across. Petra Jansen and others studied obese children for a forthcoming issue of Appetite and found that these children performed poorly on what is called chronometric mental rotation test, which measures spatial ability. Maybe some people are less astute at judging portion sizes or even their own body mass.
Social networks also powerfully influence obesity, and Kevin Lewis has a volley of studies on this subject over at his blog at National Affairs. One study suggested that enrolling in Head Start reduces a child’s odds of becoming obese. Another study found that as schools face more pressure to improve academic performance they may cut back on recess and inadvertently increase obesity levels. Another study found that students who worked at desks that encouraged standing burned more calories than those who studied at desks that forced them to sit down. Finally, researchers at the Journal of Adolescent Health compared American and Chinese students. They found that obesity rates are twice as high among students in New York and Los Angeles than among students in Hong Kong, Macau and Taipei, but students in Chinese cities were 15 percent more likely to perceive themselves as obese.
