Recently, a study looked at contestants from a popular television weight-loss show where the contestants lost weight rapidly as part of a competition.
After they were finished with the show, the contestants’ metabolisms actually became slower. And they gained the weight back over time. It was almost as if their bodies were trying to return to their original weight.
Is it the accelerated weight loss in a short time that produced these results? What about slower and more gradual weight loss over time? Is that a better way to lose weight and keep it off?
The study hasn’t provided all the answers to why the metabolism slowed down in these cases. But it is being used to help researchers understand obesity as a chronic disease and to help find ways to keep weight under control long term.
Many people who have tried to lose weight know the struggles of keeping the weight off. And it isn’t just the risk of returning to old habits that cause people to gain weight back.
Recent research shows that changes in hormones and metabolic rate seem to work to return people to their former weights.
What Is Metabolism?
Every time you eat, your body works hard to process that food so you can use it for energy. The amount of energy you burn in the form of calories is your metabolism.
The term refers to the body’s physical and chemical processes that create and use energy — things like digesting food, breathing, circulating blood and contracting muscles.
How Does Exercise Impact Metabolism?
The number of calories you use to stay alive can’t be changed. But you can boost your resting metabolic rate (RMR) through exercise and physical activity. Activity represents as much as 15 to 30 percent of your daily energy expenditure.
And this is where exercise, both aerobic and strength training, comes in. Body composition — the ratio of muscle to fat — has a lot of influence on metabolism.
How so? Because muscle is more metabolically active than fat. Pound for pound, muscle burns 30 to 50 calories more than fat a day.
How Does Cutting Calories Affect Metabolism?
We lose weight when we burn more calories than we eat, so managing your calorie intake is an important part of controlling your weight. But be careful how much you cut back.
In studies involving fasting participants or patients with anorexia, both resulted in a slower metabolism.
The slowed metabolism could be reversed over time by increasing calorie intake. However, in anorexic patients, other long-lasting complications including short stature, infertility and osteoporosis were a factor.
What Can You Do?
So how can you lose weight and keep it off? The most effective way to lose weight is to eat less and exercise more. But what can you do about your metabolism if your body seems to want to return to its former weight?
Perhaps it is slow and steady that will win the weight loss race. By slowly increasing your physical activity and strength training over time, you can boost your metabolism and help keep the weight off.
It may take you some time, three months or more, to see positive changes in your metabolism. Talk to your doctor if you continue to have questions about weight management and your metabolism.
Sources: “Persistent metabolic adaptation 6 years after ‘The Biggest Loser' competition,” Obesity: A Research Journal, 2016; “After ‘The Biggest Loser,’ Their Bodies Fought to Regain Weight,” The New York Times, May 2, 2016; "The Endocrinopathies of Anorexia Nervosa," Endocrine Practice, 2008; “Can you really change your metabolism?” NBCnews.com, 2006; Mayo Clinic, 2014; Centers for Disease Control and Prevention, 2015