Yo-yo dieting could have lasting implications

The unhealthful but popular practice of yo-yo dieting may have serious ramifications on the body, a study finds, which may make those who eat this way more vulnerable to packing on the pounds.

In the study, released Tuesday in the Journal of Neuroscience, mice were randomly assigned to a calorie-restricted diet, in which they ate 75% of the average amount of calories designed to produce a 10% to 15% weight loss, or to a regular diet with no such restrictions.

Under stressful situations the dieting mice had escalated amounts of the stress hormone corticosterone, and exhibited symptoms of depression. There was a transformation in the DNA of the mice as well&--genes that control eating and stress had changed, and those changes remained after the mice ate enough to go back to their normal, higher weights.

While under stressful circumstances the dieting mice ate more fatty foods than mice that had not dieted.

“These results suggest that dieting not only increases stress, making successful dieting more difficult, but that it may actually ‘reprogram’ how the brain responds to future stress and emotional drives for food,” said study co-author Tracy Bale of the University of Pennsylvania, in a news release.