After revealed that Biggest Loser contestants struggled to keep the weight off because the dramatic change severely slowed their metabolism, of the show's participants shows that in order to keep off a significant amount of weight, the contestants needed to log more time exercising than public health guidelines suggest.
Dr. Jennifer Kerns, a contestant on Season 3 of the Biggest Loser, is now a an obesity specialist at the Veterans Affairs Medical Center in Washington and co-author of the study, which followed 14 participants from the show.
Dr. Kerns has kept off 100 pounds by exercising on an elliptical for 35 to 40 minutes each day and tracking everything she eats.
"My natural tendency is to regain," she .
In the study, those who managed to keep off the weight they lost did 80 minutes of moderate activity—like walking— or 35 minutes of vigorous exercise—like running—on average per day.
To compare, the Centers for Disease Control and Prevention calls for 75 minutes a week of vigorous exercise, or 150 minutes a week of moderate exercise for healthy adults to maintain their weight.
These findings show that because significant weight loss slows down the metabolism, these participants needed to exercise much more than the average person to maintain their weight loss, according to Kevin Hall, who is the lead author of the study and chief of the Integrative Physiology Section at the National Institute of Diabetes and Digestive and Kidney Diseases.
The people in the study who successfully kept the weight off, "are countering the drop in metabolism with physical activity," Hall said.
While the study, which was published on Tuesday in Obesity, would need to be replicated with a larger group of people to confirm what they found, "the findings here are important," Rena Wing, a psychiatry professor at Brown University told the New York Times.