Leucine for Weight Loss

Known as the building blocks of protein, amino acids comprise a protein molecule and are used by the body to perform different functions. Leucine, which can be used interchangeably with the term isoleucine, is an amino acid that has been shown to improve weight-loss results for dieters when compared with other diets that restrict protein intake. Knowing how leucine can help you lose weight can improve your weight-loss efforts.

Significance

Your body relies on amino acids -- the building blocks of protein -- to build and maintain healthy muscles. Leucine is an example of an amino acid known as an essential acid, meaning your body requires it in order to sustain your life's functions. Because your body does not make leucine on its own, you must consume leucine in your daily diet.

Research

The link between weight loss and leucine was identified in a 2003 research study published in The American Society for Nutritional Science. Led by University of Illinois Urbana-Champaign researcher Donald K. Layman, the study examined the effects of a weight-loss diet high in leucine intake. The study enrolled human participants who were separated into carbohydrate and protein -- leucine -- groups. The participants who ate at least 10 g of leucine-containing foods per day experienced a greater weight loss in body fat and improvement in lean muscle tissue.

Food Sources

Leucine food sources for weight loss include soybeans, lentils, cowpeas, round beef, peanuts, pork salami and salmon. Other leucine-containing foods include shrimp, almonds, chickpeas, sesame seeds, flax seeds, walnuts and hummus. Sheep, goat, and cow's milk also contain leucine.

Expert Insight

Some dieters think a low-fat diet is the way to facilitate weight loss. Layman's research indicates that healthy protein sources may be a better focus. "Traditionally, people have built a diet around low-fat foods, instead of high-quality protein foods. Study participants following the moderately high protein plan, which I call the 'Sensible Solution,' were twice as effective in maintaining lean muscle mass," Layman said. "Muscle helps burn calories, but it is often compromised during weight loss."

Benefits

While some diets have the tendency to break muscle down to compensate for lost nutrients, a diet high in leucine was shown to stimulate muscle protein synthesis, even when food was restricted, according to the University of Illinois study. Because muscle burns more calories than fat, having lean muscle helps you to experience greater calorie-burning while dieting, equaling greater weight-loss results.