A low-carbohydrate diet prompts spontaneous calorie cutting, according to a strictly controlled clinical study.
The study, by researchers at Temple University School of Medicine in Philadelphia, shows that water loss, metabolism and boredom likely aren't the reason why people on the Atkins diet lose weight.
"When carbohydrates were restricted, study subjects spontaneously reduced their caloric intake to a level appropriate for their height, did not compensate by eating more protein or fat, and lost weight," says lead researcher Guenther Boden.
"We concluded that excessive overeating had been fueled by carbohydrates."
Boden set out to study how low-carbohydrate diets affect weight, appetite and blood sugar in obese diabetics.
The study involved a group of 10 obese people with type 2 diabetes who followed the Atkins diet for two weeks, cutting their carbohydrate intake to 20 grams per day with unlimited protein and fat.
The study was conducted in a clinical research center where every calorie eaten and spent was measured.
"When we took away the carbohydrates, the patients spontaneously reduced their daily energy consumption by 1,000 calories a day," says Boden.
"Although they could have, they did not compensate by eating more proteins and fats and they weren't bored with the food choices.
The carbohydrates were clearly stimulating their excessive appetites."
Participants also had improved glucose levels and insulin sensitivity, as well as lower triglycerides and cholesterol.
The research is reported in the Annals of Internal Medicine.