Short-term overeating did increase visceral fat slightly — that’s fat that surrounds the body’s organs and is considered unhealthier. But there wasn’t a significant increase in overall weight and fat mass, the researchers said.
Fasting levels of blood sugar and production of insulin didn’t change in response to the short-term overeating, the study found.
“The body copes with short periods of overeating with additional carbohydrates and makes adjustments by shifting metabolism towards utilizing these excess carbohydrates,” Wadley explained.
Chronic overeating, however, did increase total body fat and visceral body fat. It also produced higher levels of blood sugar and insulin response after eating. It didn’t alter fasting glucose levels, however.
Would the study’s findings apply to people who were older, or maybe less fit to start with?
Wadley wasn’t sure because the study only looked at young people.
“Our participants were young and within a healthy weight range. It’s possible their bodies are better able to cope with the oversupply of food,” he said. Wadley added that he’d like to follow an older or overweight group to see if they’re more susceptible to the effects of overeating.
Registered dietitian Samantha Heller, from NYU Langone Health in New York City, said she wasn’t surprised to see that younger people at a healthy weight rebounded quickly. She said people in their 40s and older might find they have more trouble after holiday splurges.
But, she noted, even these young men added some unhealthy visceral fat from short-term, large high-calorie meals.
“Visceral fat causes more problems, and from this study we don’t know how long those increases lasted once they went back to eating normally,” said Heller, who played no role in the study.
Still, if you’re overeating once or twice a year, Heller said, you’ll likely be just fine. “But if it’s a few times a week, that’s a problem, and at some point, it will catch up with you. Our bodies aren’t designed for large amounts of consistently unhealthy foods,” she said.
The study was recently published online in the American Journal of Physiology–Endocrinology and Metabolism.