Column by John Parrillo from Parrillo Performance.
Question: I’ve heard so many things about how much protein is enough and how much is too much. Can you clear up some of this confusion about protein and amino acids.
We’ve been getting a barrage of calls and questions lately about protein. “Can’t the body only digest 50 grams of protein a day? Isn’t too much protein bad for you? Can too many amino acids be harmful?” To address these questions, let’s take a look at what science says. The amount of protein actually required by bodybuilders is as hotly debated as the entire subject of nutrition. The National Research Council sets the recommended daily allowance (RDA) at 0.8 grams per kilograms of body weight a day – the equivalent of 0.36 grams per pound of body weight a day. Based on the RDA, a 200-pound bodybuilder would require 73 grams of protein a day.
Unfortunately the RDA was established with average people in mind – not athletes. Protein supplies nutrients called amino acids which are required for every metabolic process. All muscles and organs, in fact, are made from amino acids. Like most athletes, bodybuilders have higher requirements for protein than the average person. Without enough protein, you cannot build muscle, repair its breakdown after training, or drive your metabolism. Various studies indicate that weight training athletes need greater amounts of protein. In one study, for example, ten weight lifters trained intensely and consumed 0.9 grams of protein per pound of body weight a day. Four of these athletes were found to be in negative nitrogen balance.
In another study, weight lifters who increased their protein intake from 1.0 to 1.6 grams per pound of body weight a day were able to increase both strength and lean mass. Serious bodybuilders train aerobically as well, and this places some particular demands on the protein needs of the body. Prolonged aerobic exercise, for example, can burn amino acids, after the body uses up its stored carbohydrate for energy, thus elevating protein requirements. Aerobic training in a protein-deficient state can lead to a condition called “sports anemia,” in which red blood cells and serum iron levels are reduced. During training muscle fibers are damaged and must be repaired following the exercise period. If your protein intake is low, the body draws on red blood cells, hemoglobin, and plasma proteins as a source of protein for muscular repair. When this happens, little protein is left to rebuild red blood cells at the normal rate, and sports anemia can be the result. Clearly, bodybuilders must include ample protein in their diets to promote muscular fitness. Individual protein needs vary and depend on a number of factors, including a bodybuilder’s training intensity and level of conditioning. I have seen many bodybuilders improve their physiques by increasing their protein intake to as high as 2.5 grams per pound of body weight a day – nearly seven times the RDA.
Based on our experience at Parrillo Performance, hard training bodybuilders can achieve excellent results by consuming 1.25 to 1.5 grams of protein per pound of body weight a day. On our program, one gram of your protein intake per pound of body weight should come from lean protein sources such as lean white meat poultry, fish, and egg whites; The other . 25 to .5 per pound of body weight should come from vegetables, particularly beans, corn and legumes. Avoid red meats and egg yolks. These are high in fat which easily converts to body fat. Now about amino acids. These provide another way to take in additional protein. Amino acid formulations are especially beneficial during periods of intense training and strict dieting. To protect lean body mass, many competitive bodybuilders increase their usage several months before competition. Thebranched chain amino acids leucine, isoleucine and valine are directly involved in building muscle tissue.
By carrying nitrogen, they assist the muscles in synthesizing other amino acids to promote growth and repair. People consuming a high-protein diet should be sure to drink plenty of water and to get enough calcium. Protein metabolism generates ammonia, which is converted to urea and excreted in the urine and sweat. Drinking plenty of water aids the kidneys in removing this nitrogenous waste and dilutes calcium salts which could form kidney stones. Notably, there is no evidence suggesting that strength athletes consuming a high-protein diet have an increased incidence of kidney disease. The data suggesting that a high-protein diet contributes to the progressive nature of disease come from people with pre-existing kidney problems. Many studies have demonstrated a positive correlation between protein intake and urinary calcium excretion. Results are equivocal regarding protein intake and calcium absorption. Some studies show that protein improves calcium absorption while others show the opposite. Calcium balance can be maintained during high protein diets by assuring adequate calcium and phosphorus intake (at least the RDA, 800-1200 mg/day) from both diet and supplementation.