New research indicates that a high-protein, low-carbohydrate diet can be quite effective for weight loss for severely obese teenagers.

"To investigate, the researchers randomly assigned 24 severely obese teenagers to eat a high-protein, low-carbohydrate diet and 22 matched teens to eat a low-fat diet for 13 weeks. The study subjects were 14 years old on average and were at least 175 percent above ideal weight, but were free of type 2 diabetes or other serious medical problems. They were closely supervised throughout the study."

The subjects on the high-protein, low-carbohydrate diet lost 29 pounds in 13 weeks on average. Those on the low-fat diet lost 16 pounds in that time. Both groups maintained their weight loss for nine months after the study was completed.

The high-protein, low-carbohydrate diet showed no negative effect on bone mineral density, cholesterol or other measurements. Though the researchers had expected the severely obese teenagers in the high-protein, low-carbohydrate diet to have elevated LDL cholesterol levels, this was not the case. Both groups had decreased LDL (bad) cholesterol levels and increased HDL (good) cholesterol levels.

http://www.reuters.com/article/idUSTRE6303TC20100401