The effects of a sedentary, gluttonous lifestyle are hard to shake, even after the person has become an upstanding, healthy individual, a new Swedish study suggests.
Researchers found that even a short period of overeating and a lack of exercise can have lasting effects on a person's physiology and make it harder to lose weight and keep it off.
Eighteen healthy people of normal weight were given the arduous task of limiting their physical activity (to no more than 5,000 steps a day) and increasing their food intake for four weeks. The participants in this so-called intervention group ate 70 percent more food, for a total of about 5,753 calories a day, over the study period.
At the study's start, the participants, whose average age was 26, had to be willing to gain between 5 percent and 15 percent of their weight in the name of science.
A second, control group ate and exercised as they normally would.
The couch-potato group added 14 pounds (6.4 kilograms) on average, with gains in both their body fat and their fat-free body mass. Six months after the group was allowed to go back to eating normally and exercising, they lost 71 percent of the gained weight, on average. [7 Diet Tricks That Really Work]
However, one year after the study period, those individuals still had more body fat than they did at the study's start.
For instance, compared with a baseline of about 20 percent body fat by weight, the gluttonous group had about 24 percent six months after the study period. And after a year, almost half of the body-fat increase was still there. Their fat-free body mass had dropped to baseline values by then.
The difference between the groups was even greater after 2.5 years, when participants in the overeating group showed a gain of 6.8 pounds (3.1 kg) from the baseline. Meanwhile, the control group didn't show any significant weight gain.
"The long-term difference in body weight in the intervention and control groups suggests that there is an extended effect on fat mass after a short period of large food consumption and minimal exercise," said study researcher Åsa Ernersson of Linköping University in Sweden.
The research was funded by the University Hospital of Linköping Research Funds, Linköping University, Gamla Tjänarinnor, Medical Research Council of Southeast Sweden, and the Diabetes Research Centre of Linköping University. The results will be published in an upcoming issue of the journal Nutrition & Metabolism.
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Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.