Extreme eaters show abnormal brain activity
Pictures of food revs up reward circuits in the obese, slows them down in severely underweight
CHICAGO — Certain brain areas are sluggish in people who eat too little and hyperactive in people who eat too much, a new study finds.
The results, presented April 3 at the annual meeting of the Cognitive Neuroscience Society, are based on brain activity in people who ranged from dangerously thin to morbidly obese. The findings help clarify the complicated relationship between the brain and food, and may even offer ways to treat conditions such as anorexia and obesity, said study coauthor Laura Holsen of Harvard Medical School and Brigham and Women’s Hospital.
Although scientists have looked for brain differences among particular groups of people with disordered eating habits, no previous study had compared responses to food across such a wide spectrum. “It’s important to study the extremes, because the biology is clearer in those individuals,” said psychologist Susan Carnell of the New York Obesity Nutrition Research Center, St. Luke’s-Roosevelt Hospital Center and Columbia University. “That helps us understand normal weight variation.”
One of five groups studied by the researchers consisted of people with anorexia, defined as being 85 percent or less of a healthy weight. A second group enlisted people who formerly had anorexia but had recovered to a healthy weight. Healthy people with a normal weight formed the third group; the fourth was composed of people who were obese.