What are protein supplements supposed to do?
Step into any health-food store and you're likely to see stacks of protein-packed powders and bars, often accompanied by pictures of people with action-figure bodies. The message is clear: If you want to trade in your relatively normal body for the Mr. (or Ms.) Olympiad model, you can't live without products like Ultra Body-Building Protein Powder and Promax Bars. After all, it takes protein to build muscles, so megadoses of protein must result in megamuscles, right? Before buying into that premise, take a close look at the facts. In the end, you may not lose your normal body, but you won't lose your money either.
How much protein does an athlete really need?
It's true that weight lifters and other high-powered athletes need more protein than the rest of us. Recent studies suggest that a 200-pound athlete should eat between 120 and 180 grams of protein every day, while a 200-pound Internet writer can get by quite nicely on only 70 to 90 grams. To put it in perspective, a shot-putter could reach his maximum daily requirement by filling his plate with these items: eight ounces of firm tofu, one broiled pork chop, and one cup each of roasted peanuts, cottage cheese, chickpeas, oat bran, and ricotta cheese. The writer could skip the tofu, pork chop, and cottage cheese.
Of course, athletes also need more calories than the rest of us. A weight lifter or football player can easily go through 4,000 calories per day, compared with the roughly 2,000 calories a moderately active person burns. And in this country, it would take a real effort to consume 4,000 calories without getting 180 grams of protein. The typical American eats 50 to 70 percent more protein than necessary, and almost all athletes get their daily requirement in what they eat.
Whether you want to lose weight, gain weight, or hold steady, the Mayo Clinic recommends that you stick to the same formula: 45 to 65 percent of your calories should come from complex carbohydrates, 20 to 35 percent should come from fat, and only 10 to 35 percent from protein.
Do protein supplements help build muscle and strength?
Scientists have put protein supplements through rigorous tests, and the results have fallen far short of the promises. A study published in 2010 assessed changes in the strength of middle aged and older men following 14 weeks of resistance training, either with or without protein and/or creatine supplements. All the groups significantly increased muscular strength and added muscle mass with no additional benefits from creatine and/or protein supplementation. A 10-week study of 33 men in 2004 similarly showed no difference in strength between those who consumed a protein supplement and those who didn't.
After reviewing these studies, physician Richard B. Krieder of the University of Memphis reached the following conclusion: "Although it is important for athletes to get an adequate amount of protein . . . consuming additional amounts of protein does not appear to promote muscle growth."
Are protein supplements dangerous?
A little extra protein for most people won't do much harm, so feel free to have a protein bar now and then. But you can definitely overdo it. According to a report in the journal Clinical Pharmacy, a protein overload can cause stomach trouble, dehydration, gout, and calcium loss, as well as damage to the liver and kidneys. There's no clear-cut line between safe and dangerous amounts, but experts agree on this: Whether you're a writer or a weight lifter, it's better to get your protein from a balanced diet than from a supplement.
Kreider RB. Dietary supplements and the promotion of muscle growth with resistance exercise. Sports Med. 1999 Feb;27(2):97-110.
Maughan R. The athlete's diet: nutritional goals and dietary strategies. Proc Nutr Soc 2002 Feb;61(1):87-96.
Burke LM. Energy needs of athletes. Can J Appl Physiol 2001;26 Suppl:S202-19.
Tarnopolsky MA et al. Evaluation of protein requirements for trained strength athletes. Journal of Applied Physiology. 1992. 73: 1986-1995.
Lemon PW et al. Protein requirements and musclemass/strength changes during intensive training in novice bodybuilders. Journal of Applied Physiology. 1992. 73: 767-775.
Mayo Clinic. Healthy diet: End the guesswork with these nutrition guidelines. February 2009.
Protein requirements and supplementation in strength sports. Nutrition. July 2004. 20(7-8):689-95.
Chromak JA, et al. Effect of a 10-week strength training program and recovery drink on body composition, muscular strength and endurance, and anaerobic power and capacity. Nutrition. 2004. May 20 (5); 420-427.
American Dietetic Association. Strength building and muscle mass.
Bemben MG, Witten MS, Carter JM, Eliot KA, Knehans AW, Bemben DA. The effects of supplementation with creatine and protein on muscle strength following a traditional resistance training program in middle-aged and older men. J Nutr Health Aging. 2010 Feb;14(2):155-9.