January 4, 2012
Add More Protein To Your Diet To Avoid More Body Fat
While it has been known for a long time that excess calories can lead to extra pounds, a new study, published Tuesday in the Journal of the American Medical Association, suggests that eating too little protein could also put more fat on your body, reports The Los Angeles Times.
A team of researchers, led by Dr. George Bray of the Pennington Biomedical Research Center in Louisiana, looked at how three diets with different protein contents influenced weight gain and body makeup. The findings, the team noted, could have larger implications for combating obesity.
For the study, researchers put 25 people between the ages of 18 and 35 on a weight maintenance diet for 13 to 25 days, after which they were assigned to one of three diets for an 8-week period: one had 5 percent calories from protein (low protein), one had 15 percent calories from protein (normal protein), and one had 25 percent calories from protein (high protein). All three diets included the same amount of carbohydrates, and fat made up the difference in the calories.
The researchers purposely overfed the participants by about 950 calories per day (roughly 40 percent more than they were previously eating) during the initial phase of the study. All participants stayed at an inpatient facility to ensure meals and calories were carefully controlled.
Everyone gained weight during the overeating period. However, those in the low-protein diet lost 2.2 pounds of muscle mass, while those in the normal- and high-protein groups gained muscle mass during the overeating period. Muscle weighs more than fat, which is why they gained more weight.
All three groups gained body fat. But in the low protein diet, more than 90 percent of excess calories were stored in the body as fat, while in the normal and high protein groups about 50 percent of the extra calories were stored as fat.
The normal and high protein groups also saw a substantial increase in their resting energy expenditure -- how many calories the body burns while at rest. The low protein group´s resting energy expenditure did not change significantly during the period when calories were increased. Generally, the more fit a person is and the more muscle mass he or she has, the higher the resting energy expenditure.
“Most people are overeating and for those people who are, they need to pay attention to what they are putting into their mouths,” said study co-author Leanne Redman, an assistant professor of endocrinology at Pennington Biomedical Research Center. “If you overeat a high-fat, low-protein diet, you may gain weight at a lower rate, but you are gaining more fat and losing more muscle.”
The composition of the weight -- lean muscle or fat -- may be even more important than the number on the scale or body mass index, Dr. David Heber, director of the Center for Human Nutrition at the University of California, Los Angeles, said in an accompanying editorial with the study.
“Calories count,” he said. Heber encourages a high-protein, low-fat diet that is rich in colorful fruits and veggies. “We are talking about lean protein such as white-meat chicken, ocean fish, turkey, egg whites and certain protein powders. Protein is more satiating, and helps reduce appetite.”
“This study provides support to the calories-count message as it relates to percent of body fat. I find the conclusion of this study especially helpful in encouraging people to be aware of the calories they consume and to avoid focusing on just where those calories come from,” Connie Diekman, director of university nutrition at Washington University in St Louis, told USA Today. Diekman was not an author of the new study.
On the Net:
- Journal of the American Medical Association
- Pennington Biomedical Research Center
- University of California, Los Angeles