Can a High-Protein Diet Help You Lose Weight?

Low-carb diets are last year's news, but high-protein diets are emerging as the latest buzz in weight control. That's because emerging research has hinted that protein may be able to satisfy hunger better than either fats or carbohydrates.

Could a high-protein really help you eat fewer calories (and thus lose weight) by keeping your hand out of the cookie jar? WebMD asked some experts for their views.

What Studies Show

Participants in a study recently published in the American Journal of Clinical Nutrition reported greater satisfaction, less hunger, and weight loss when fat was reduced to 20% of the total calories in their diets, protein was increased to 30%, and carbs accounted for 50%. The study participants ate some 441 fewer calories a day when they followed this high-protein diet and regulated their own calorie intake.

Another study, reported in the Journal of Nutrition, showed that a high-protein diet combined with exercise enhanced weight and fat loss and improved blood fat (lipid) levels.

"Our research suggests that higher-protein diets help people better control their appetites and calorie intake," says researcher Donald Layman, PhD, a professor at the University of Illinois at Urbana-Champaign.

"Diets higher in protein [and] moderate in carbs, along with a lifestyle of regular exercise … have an excellent potential to reduce blood lipids [and] maintain lean tissue while burning fat for fuel without dieters being sidetracked with constant hunger."

Researchers don't understand exactly how protein works to turn down appetite. They surmise that it may be because a high-protein diet causes the brain to receive lower levels of appetite-stimulating hormones.

"We are not exactly sure of the mechanism for satiety, whether it is due to [eating] fewer carbs and/or the specific protein effect on hunger hormones and brain chemistry," Layman says.

And more research is needed before experts can make sweeping recommendations that people boost the protein in their diets, says American Dietetic Association president Rebecca Reeves, DrPH, RD, an obesity researcher at the Baylor College of Medicine.

"I think it is fascinating and intriguing, yet we need the evidence that higher-protein diets are more effective over the long term," Reeves says.

How Much Do You Need?

We need protein at all stages of life, for a variety of bodily functions. It's the major component of all cells, including muscle and bone. It's needed for growth, development, and immunity to fight off infections and protect the body.

The Institute of Health's Dietary Reference Intake (DRI) recommendations allow for a wide range of protein intake -- anywhere from 10% to 35% of total calories -- for normal, healthy adults. For example, on an 1,800 calorie diet, you could safely consume anywhere from 45 grams (that's 10% of calories) to 218 grams (35%) of protein per day.