The analysis, published in the August 2021 edition of the research journal Obesity, reinterpreted data collected from contestants of the show. In a previous study, the author, Kevin D. Hall, noted that contestants experienced a dramatic slowing of their metabolisms after losing a lot of weight. He also noted that regaining the lost weight doesn’t restore the metabolism to its previous level, which helps explain why it’s so difficult to keep weight off after losing it.
In the new study, Hall attempts to explain those findings in more depth, using what he calls the “constrained model of human energy expenditure.” That model states that the body aims to keep an even keel in terms of energy expenditure and will turn down its metabolic rate when weight loss occurs.
From an evolutionary standpoint, this is great news – our hunter-gather ancestors could rely on the body’s precise energy-balance-keeping mechanism to help them get through lean times. But in the modern age, where far too many calories are on constant offer, that survival mechanism may be contributing to rising rates of obesity.
Recent Studies Emphasis Exercise
It’s a dynamic and complicated picture, but “the analysis appears to support the importance of continual physical activity for long-term weight loss and maintenance,” says Lisa Cooper, a registered dietitian with the Orlando Health Center for Health Improvement.
In other words, if you lose weight, you’ll need to maintain an exercise routine long term to keep it off. The analysis notes that “the contestants who sustained the greatest increases in physical activity expenditure at six years also maintained the greatest weight losses,” which suggests that an ongoing exercise regimen can help you keep off the weight you lose.
This is consistent with findings from a range of other studies, says Shaun Carrillo, lead wellness coach with Providence St. Joseph Hospital in Orange County, California. “There are countless studies supporting the value of exercising during weight loss.”
For example, on 2018 study, showed that “70% of people who lost weight and kept it off engaged in regular exercise programs. Of the people who didn’t keep it off, less than 30% engaged in regular exercise programs.”
