Everyone knows that in order to maintain weight, one has to balance fuel intake (food) with energy output (exercise, plus controlling temperature and running body processes such as digestion). But straying from that ideal ratio now and then can’t hurt as long as you return to your equilibrium, can it? Unfortunately, it turns out that a four-week lapse of intake-output balance can affect fat mass over two years later.
Asa Emersson, Fredrik Nystrom and Torbjorn Lindstrom of Linköping University Sweden gave 18 individuals a diet that was 70% greater in calories than normal for four weeks. During that time, the subjects were allowed only limited amounts of exercise. A control group ate and exercised normally.
The binging group gained weight, as expected, but were mostly able to shed that excess weight by six months after returning to their normal eating and exercising regiments. However, even two and a half years later, the binging group had more fat mass than the control group. The overeating had somehow changed each subject’s physiology, which persisted for at least a few years.
Four weeks is a long deviation for people who normally maintain control over their diet and exercise programs. I’d be interested to know what happens when people overindulge for a day or two, or skip exercising for a week. Unfortunately, I suspect that I now know the answer.