I’m sure many people can relate to this scenario: You’re doing great with eating healthy and exercising regularly, and you’re steadily working toward your weight loss goals. Then your week-long tropical vacation arrives, and suddenly all of those newly formed habits are out the window. The most exercise you get all week is walking from your lounge chair to the refrigerator for another drink, and snacks and fried foods are a daily part of the menu. You arrive home a few pounds heavier than when the week began, but you figure its all part of the process. It takes some time, but eventually you get back on track and begin again. A new study says it might not be that simple, because short-term lapses of overeating could make long-term weight loss more difficult.

The study, published in the journal Nutrition and Metabolism, looked at 12 men and 6 women in their 20’s who were a normal, healthy weight. For one month, participants were restricted to no more than 5,000 steps per day and increased their calorie intake by 70 percent (eating an average of 5,750 calories per day.) Another group made no changes to their diet or exercise routines.

At the end of the month, participants had gained an average of 14 pounds and 4% body fat. Over the next six months, participants lost most of that weight, but a year later, they still had a noticeable gain in fat mass. This means that some of the fat stuck around even though they lost weight and returned to their pre-study healthy routines. Two-and-a-half years later, fat mass gains were even greater (an average of 7 pounds) for study participants, but there was no change in the control group’s body composition.

"Based on the findings, the researchers conclude that a brief period of excessive over-eating, coupled with reined-in activity, may change body composition and lead to a significant boost in body fat levels. And these changes appear to endure, despite a return to healthier behaviors." Although this study was extreme, since most people won’t become sedentary and increase their calorie intake by 70% for a month at a time, the results are interesting. It adds validity to the theory that yo-yo dieting can make weight loss more difficult in the long run.

What do you think?