“The Biggest Loser” Study Predicts Sustained Weight Loss Through Modest Changes in Diet and Exercise
With a validated computational model for predicting weight loss, a research study has quantiied
the dramatic diet and exercise intervention strategy
employed in “The Biggest Loser” television program.
It found that this intervention would not be sustainable
over time, but a more modest and feasible diet and
exercise could maintain the weight loss. “The Biggest
Loser” program, although highly successful, has been
criticized for portraying an extreme diet and exercise
intervention regimen that could raise unrealistic
expectations for weight loss. The program shows
obese adults losing large amounts of weight over
several months, initially isolated on a ranch, followed
by an extended period at home.
Scientists took advantage of this cost-eficient
opportunity to study the television program’s 16 obese
contestants already engaged in an intensive lifestyle
intervention. As part of the program, researchers
measured body fat, total energy expenditure and
resting metabolic rate—the energy burned during
inactivity—three times: at the start of the program, at
week 6, and at week 30, which was at least 17 weeks
after participants returned home. Participation in the
program led to an average weight loss of 128 pounds,
with about 82 percent of that coming from body fat,
and the rest from lean tissue like muscle. Preserving
lean tissue, even during rapid and substantial weight
loss, helps maintain strength and mobility and reduces
risk of injury, among other beneits.
A scientist at NIDDK then used a mathematical
computer model of human metabolism to calculate
the diet and exercise changes underlying the observed
body weight loss. Because the TV program was not
designed to directly address how the exercise and diet
interventions each contributed to the weight loss, the
computer model simulated the results of diet alone and
exercise alone to estimate their relative contributions.
At the competition’s end, diet alone was calculated
to be responsible for more weight loss than exercise,
with 65 percent of the weight loss consisting of body
fat and 35 percent consisting of lean mass like muscle.
In contrast, the model calculated that exercise alone
resulted in participants losing only fat, and no muscle.
The simulation of exercise alone also estimated a small
increase in lean mass despite overall weight loss. In
addition, the simulations suggest that the participants
could sustain their weight loss and avoid weight regain
by adopting more moderate lifestyle changes—like 20
minutes of daily vigorous exercise and a 20 percent
calorie restriction—than those demonstrated on the
These indings suggest that a more moderate weight
loss strategy, rather than the extreme lifestyle
intervention depicted in “The Biggest Loser,” would
be preferable for sustained weight loss in many people
who are obese.
Hall KD. Diet versus exercise in “The Biggest Loser” weight
loss competition. Obesity (Silver Spring) 21: 957-959, 2013.