STUDY: Just One Week of Overeating Can Change Your Body

Eating more and exercising less—even for just a week—can cause unwelcome changes to your body, according to a recent study.


Even a brief respite from exercise, combined with a surge in overeating, can have negative effects on your body, according to research published in The Journal Of Physiology.

Researchers rounded up a group of 26 healthy young men (average age, 25) who exercise at least three times a week for 30 minutes each day. Half of the participants were instructed to decrease their activity to less than 4,000 steps a day and simultaneously increase their energy intake by 50 percent. The other half were instructed to do the same, but also to undertake a daily 45-minute run at 70 percent of their Vo2 max and to increase their energy intake by 75 percent to replenish the energy deficit they incurred during their runs.

The researchers tested both groups' blood insulin measurements and took biopsies of their adipose (fat) tissue before the test and after a week on the protocol. Although both groups had increased their energy intake, there were major differences between them. The inactive group showed a decline in their body's ability to regulate insulin levels, while the group that exercised maintained their ability to regulate insulin. According to the study, biopsies of the adipose tissue showed that "short-term positive energy balance from overfeeding and under-activity resulted in impaired metabolic outcomes and alterations in the expression of several key genes within adipose tissue involved in nutritional balance, metabolism and insulin action."

"If you are facing a period of over-consumption and inactivity, then our study shows that a daily bout of exercise will prevent many of the negative changes from taking place even though you are gaining weight," said the paper's senior author Dr. Dylan Thompson in a press release.

Photo Credit: Getty Images // Thinkstock