Summer is here, which means it's not only time to get some natural vitamin D via sunshine, it's time to do a quick check on any weight management goals you may have had.Â Recent research suggests that a naturally occurring component found in high protein foods may help maintain muscle mass.Â Why is this important?Â Outside of the obvious reasons for muscle, it also burns about 3x more calories than fat1!Â What is this seemingly magical ingredient - an amino acid called leucine.
First, some background about protein.Â Protein is made of smaller "building blocks" called amino acids, of which leucine is one.Â It is one of nine essential amino acids that we must get from our diet because our body cannot make them.Â The only type of food that contains all nine essential amino acids comes from animals products.Â Plant foods may contain this amino acid in varying amounts, which tends to be lower than the amount found in animal products.
Recent studies suggest that leucine is crucial when it comes to identifying the quality of protein that influences muscle mass and body composition2, how much body fat you have, and whether the calories you eat will be deposited as fat or muscle3.Â Â Simply stated, the higher the leucine content of a food, the better it may be at increasing or maintaining muscle mass while decreasing body fat!Â Keep in mind; it takes action on your part to make this occur, which means exercise.Â Timing your intake of this amino acid is important.Â The standard recommendation is approximately 1 gram per 77 pounds of body weight per day split between pre/post strength workouts.
If you prefer to keep your consumption of leucine from food the best source is animal products.Â To obtain about 2g/day for the average person you can consume:
- 2 Â½ cups of milk (skim, 1% or 2%)
- 3-4 oz of cooked poultry, beef, fish, game meat (such as elk, bison)
- 4 servings of soymilk or other soyfoods
As I mentioned above, in order to make positive changes in your body composition, exercise and a healthy diet are also imperative.Â Train hard, eat smart and enjoy the summer!
1.Â Â Â Â Â Â Wolfe RR. The underappreciated role of muscle in health and disease. Am J Clin Nutr 2006;84(3):475-82.
2.Â Â Â Â Â Â Norton LE, Layman DK, Wilson GJ, et al. Leucine contents of isonitrogenous protein sources predict changes in body composition and muscle mass in rats. FASEB J 2010 24:97.5 (abstract)
3.Â Â Â Â Â Moulton C, Norton L, Wilson G, Layman DK. When a calorie isn't just a calorie: isocaloric, isonitrogenous diets containing different protein sources produce differential body composition outcomes in rats. FASEB J 201024:220.6 (abstract)