A study published this week in the Journal of the American Medical Association suggests that people who consistently consume more calories than they burn each day will lose lean muscle and accumulate body fat more easily if their diets contain too little protein and too much fat and carbohydrates.



Researchers studied 25 healthy men and women between 2005 and 2007. Their average body mass index (BMI) ranged from nearly 20 to nearly 30 (normal BMI is between 18.5 to 24.9).

Participants first ate a weight-stabilizing diet for 13 to 25 days before being assigned to one of three groups: a 5%, 15%, or 25% protein diet supplemented with low carb protein supplements. During the next eight weeks, they were fed one of the three protein levels in a diet that had about 1,000 extra calories a day.

The researchers evaluated their weight, body composition, and resting energy expenditure before and after the study. They discovered that while all groups did gain weight, the low-protein group was found to have gained the least (average 7 pounds); the normal-protein group gained 13.3 pounds; and the high-protein group gained 14.4 pounds.

These findings could help experts advise people on how to eat to avoid weight gain and obesity and to maintain lean body mass.

via WebMD