MINNEAPOLIS (WCCO) — Every Thanksgiving, many of us will pack on a few of pounds we may have shed earlier in the year. It can sometimes seem like our bodies are working against us.
So, why is it hard to keep off the weight we’ve lost? Good Question.
“It is really true,” says Dave Bernlohr, chair of the biochemistry, molecular biology and biophysics department of the University of Minnesota. “It’s unfair and cruel and works against everything we like to do.”
In a 2016 study published in the journal Obesity, researchers found 13 of 14 contestants regained the weight they’d lost.
“If you lose weight too quickly, the body will try to reset or maintain its initial set point,” Bernlohr says.
The fat cells in our bodies secrete hormones. One of those hormones is leptin and it stops a person from feeling hungry. The more fat a person has, the more leptin they have, so when someone loses weight, they lose that satiety signal.
“You get hungry and your body is telling you you’re in good shape, so let’s store,” Bernlohr says.
The body will then signal the muscles to be more efficient and burn fewer calories. That lowers a person’s metabolism.
Researchers in the “Biggest Loser” study found the contestants’ metabolic rate remained suppressed even after they’d regained the weight.
Age, hormones, sex, genetics and gut bacteria can also affect a person’s metabolic rate.
Dr. Bernlohr says losing weight more slowly can combat some of the tendency to regain the weight. Essentially, the body can adjust to its newer set points more easily with time.
Still, though, people who lose weight cannot go back to eating what they did before the weight loss.
“If you lose weight, in order to keep it off, you have to keep a little bit lower caloric intake than you want to and you have to augment that with some exercise,” Bernlohr says.