FRIDAY, Oct. 19, 2012 (HealthDay News) -- A combination of exercise and healthy eating is better than dieting alone in reducing body fat and preserving muscle in adults, according to researchers who analyzed data from 11 participants on the reality TV show "The Biggest Loser."
The program features obese adults who attempt to lose large amounts of weight over several months.
The 11 participants' body fat, total energy expenditure and resting metabolic rate (energy burned when inactive) were measured at the start of the program, at week 6 and at week 30. The participants had an average weight loss of 128 pounds, with about 82 percent of that coming from body fat and the remainder from lean tissue such as muscle, the investigators found.
Preserving muscle during weight loss offers a number of benefits, including lowering the risk of injury, and promoting strength and mobility, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) researchers.
For the study, the investigators used a mathematical computer model of human metabolism to create simulations of the diet and exercise that led to the participants' weight loss. The computer program calculated that diet alone was responsible for more weight loss than exercise, with 65 percent of the weight loss from body fat and 35 percent from lean mass (including muscle).
On the other hand, exercise alone led to the loss of only fat, with no muscle loss, and also resulted in a small increase in lean mass despite overall weight loss, the study authors explained in an institute news release.
The findings also indicated that the participants could avoid regaining weight by adopting more moderate lifestyle changes than those shown on the television program; for example, by maintaining 20 minutes of vigorous exercise a day and a 20 percent reduction in calorie intake.
"This study reinforces the need for a healthy diet and exercise in our daily lives," Dr. Griffin Rodgers, director of the NIDDK, said in the news release. "It also illustrates how the science of metabolism and mathematical modeling can be used to develop sound recommendations for sustainable weight loss -- an important tool in the treatment of obesity -- based on an individual's unique circumstances."
The study was released online in advance of print publication in an upcoming issue of the journal Obesity.
More information
The U.S. Centers for Disease Control and Prevention offers advice about healthy weight loss.
