This is a paper I wrote for school, where I had a conservative teacher. I often recommend higher amounts, and still have never come across any proof that a high protein diet damages healthy kidneys. In fact the biggest two additions to my training in the last 4 years are brutal bodyweight conditioning and consuming much higher amounts of protein. 2/12/04
Protein is an extremely important part of anyone�s diet. However, athletes have varying misconceptions about protein supplements and the amount of protein they should ingest. This paper will look at actual scientific evidence to determine the following.
1. What is protein?
2. How much protein does the athlete really need to intake?
3. Is there a reason to supplement whole foods with protein?
4. Does the athlete need to take amino acids if he/she is already eating adequate protein?
5. What is the cost of supplemental and whole food proteins?
This paper is intended to serve as a guide to correctly and effectively help athletes use protein intelligently to maximize their performance. It will be used on my bodybuilding website to serve as a rough guide to protein use in sports applications.
What is protein?
Before we examine these questions we will discuss a brief history of protein. In 1845 a European chemist named Liebig came up with the early theory that protein is the body�s main form of energy. He claimed that protein provided the energy for muscle contraction through its breakdown within muscle tissue. Dietary fat and carbohydrate were not recognized by Liebig as energy sources; instead, he thought that fat and carbohydrates were available to react with oxygen in the lungs to produce heat, thus preventing "oxygen poisoning". He believed that protein was the only truly nutritive macronutrient since it served as the structural component of skeletal muscle tissue as well as its sole energy source (#1). Research around the turn of the century proved him wrong and thus people accepted that protein is not a main energy source but a tissue builder. In modern times we know that there are twenty-one amino acids, nine of which are essential. By essential we mean that these amino acids cannot be supplied in large enough amounts by the body (from its carbohydrate intake and stored nitrogen) to meet its needs. The nine essential amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and in some histidine. Some high sources of non-animal protein are vegetables, such as beans and peas. Since we need all twenty-one aminos present in our bodies in order to grow, we must get these nine essential amino acids from our diets. We can best get a proper ratio of essential aminos by ingesting meats, milk, and soy. These foods, unlike plant proteins (except soy), can be ingested alone to get a proper ratio of essential aminos. Plant proteins need to be eaten with each other for maximum benefit. For example, grains are predominantly low in tryptophan and lysine and, thus, must be taken in with another type of protein. Two ways to measure the degree to which food provides the essential amino acids are the Net Protein Utilization Index and the Protein Equivalency Ration (#2 p154). We can see that when using these two tools, whey protein concentrate (a supplemental form whose whole food name is lactalbumin) and egg white protein give almost 100% of the needed aminos to the body. Fish and meats score around 80% and casein (the main protein in milk) and soy score about 75%. (#2 p154).
How much protein does the athlete really need to take?
The answer to this question is difficult because many experts disagree. The RDA for a male athlete around 20 years of age is .8 grams of protein per kg. of body weight. This is around .36 grams per lb. of body weight. There are two main problems with this: first, any estimates for food intake should be based on lean body mass; second, the protein level may not be helpful to athletes. When we base data on total weight, we forget that some people may be 20%, 30%, or 40% fat. Fat is not nearly as metabolically active as muscle tissue and, therefore, these recommendations should be specified for lean body weight to more accurately meet peoples� needs. However, people would need to calculate their body fat percentage and, although this isn�t difficult, does complicate the procedure. Modern research is also showing that athletes do need more protein than RDA recommendations. According to studies discussed in Nutrition: for Health, Fitness, and Sport, there are new protein recommendations made by researchers for athletes. �Several studies have attempted to determine the protein requirement for maintaining positive nitrogen balance (this means your body is getting enough protein to grow, the state of anabolism) during weight lifting. Peter Lemon in a 1996 review recommended between 1.7 and 1.8 grams of protein per kg. of bodyweight per day, whereas Mark Tarnopolsky in 1993 recommended between 1.2 and 1.76 grams of protein per kg. bodyweight. Gail Butterfield recommended twice the RDA (or 1.6 grams per kg. bodyweight) and 200 additional calories per day� (#3 188-9). These same experts had slightly different recommendations for endurance athletes, of 1.2-1.4, 1.2-1.6, and 1.26grams per kg. of bodyweight respectively. These studies were also referenced in articles on www.gssiweb.com that discussed protein needs for athletes. It is also important to address the needs of vegetarians: �According to World Health Organization (1985) recommendations, protein digestibility is reduced by about 10% in a vegetable-based diet due to the high fiber content of the diet. Accordingly, it is suggested that those who eat such diets should consume 110% of the calculated protein requirement to ensure adequate protein intakes� (#4). It is difficult for an individual to decide what is best, but it would seem that to maximize results, one should increase protein to one of the researcher�s levels. After noting results for a month, one should decrease the level of protein monthly until performance suffers and then resume the lower level of intake that yielded the initial high gains. This may be the safest option in the long run. Some new research also suggests that protein intake at twice the RDA recommendations (around 100 grams/day) is not dangerous, but that doubling this number can be harmful especially if you have a family history of liver or kidney problems. (#3 202)
Is there a reason to supplement whole foods with protein?
There are two issues to discuss: first, is it possible to get enough protein from whole foods, and second is there any benefit to supplemental proteins over food proteins? To answer the first question we must look at how much protein a person needs in a day. We will assume that a 180lb. male athlete who trains two hours per day six days per week wants to intake the maximum recommendation above of 1.76grams of protein per kg. of bodyweight. Thus, his daily intake would be 144 grams per day. According to Corinne Netzer�s Complete Book of Food Counts, there are 8.8 grams of protein in each ounce of chicken; therefore, one pound of chicken (16 oz) has about 140 grams of protein. Accordingly, this man would need to consume one lb. of chicken per day without any other protein to reach his daily needs. Obviously, this would not be the ideal way to get his daily amount, but it illustrates how that person can easily reach his daily protein needs without supplements. To discuss the second issue we must look at the differences between supplemental protein and whole food protein. There are three different forms of protein: intact or polypeptides (whole food protein), hydrolysates, (proteins that are broken into single amino acids by enzyme) and di/tripeptides. Each of these types can be argued to be best. Some claim that intact proteins are the best because the human gut evolved digesting these intact proteins. Others believe that because hydrolysates are already broken down, they can be more easily digested. The argument for free-form aminos is that they can be tailored to specific needs (#2 159). However, one would need to know exactly how much of each amino acid was needed by their body and this would not be practical. According to studies of burn patients (#5 and #6), hydrolysates may hasten nitrogen retention. During these tests free form aminos have been shown to be of no great benefit, and consequently, supplementing your diet with branch chain amino acids (especially if you are getting enough protein) would seem highly unnecessary. There is no scientific proof available that shows that BCAA�s are needed if a diet is already rich with protein. Almost all of the supplemental proteins are whey, soy, egg, milk, or some combination. Even if we debate the digestibility factor, one can get any of these proteins in abundance through whole foods with the exception of whey. Whey is part of dairy products (it is the clear fluid on top of cottage cheese) but to get a large amount through whole foods would be difficult. We know an athlete can get enough protein from excellent whole food sources, such as egg whites, but is whole food protein as quickly digested as hydrolysates and does this matter? Whole foods cannot be digested as quickly as hydrolysates and this can be important post-workout. There are numerous studies (see #3 and notes from class) that show a large dose of carbohydrates and protein after exercise can greatly restore muscle glycogen levels and help begin to repair muscle damage. If a protein is more quickly digested and distributed to the body then it can help repair muscle tissue more quickly. By this rationale a supplemental hydrolysate protein may be better than a whole food protein assuming the supplemental protein was either egg white or whey. However, new research frowns upon the use of whey protein alone. Because whey is so easily digested, new studies (#7 and #8) have shown that casein may have an advantage over whey. The first study showed that whey takes three hours to digest alone and casein six hours. Even though whey has a better amino acid ratio, the casein makes up for this because it is digested more slowly. Because of the speed at which the whey is digested, some of the aminos don�t get used for muscle protein synthesis, but instead they get used for energy. The second study proved that adding carbohydrates to protein only added 5% utilization to the protein. After all this controversy it is difficult to recommend or discourage supplemental protein. In a third new study (#9) researchers compared whey hydrolysate, pea peptide hydroylsate, glucose, and milk protein solutions and found that the size of a meal (caloric density) determines the rate at which it is processed more than the nutrient make up of the meal. However, the researchers did agree that the nature of the calories does help determine how quickly it is processed. For a serious athlete it might be good to ingest some whey or egg hydrolysate protein immediately after a workout because, even if some aminos are used for energy, some muscle repairing aminos will quickly stop the destruction working out has created. However, for the average individual or even a moderate athlete whole foods should supply plenty of adequate protein and negate any need for supplements. Whole foods can also supply extra benefits such as vitamins and minerals. Consumers should remember that supplemental proteins are all taken from whole food sources and that if one eats certain whole foods, the same value protein will be obtained.
Does the athlete need to take amino acids if he/she is already eating adequate protein?
As mentioned above, there is no proof that supplementing BCAA�s will improve performance. One such study shows that when a researcher gave a group of cyclists 18 grams of BCAA�s, it didn�t delay the amount of time until fatigue while riding exercise cycles (#10). However, there have been other studies that show increased mental performance, but since there is further research needed, there is no evidence to suggest a need to supplement with BCAA�s.
What is the cost of supplemental and whole food proteins?
The cost naturally depends on where you shop and whether you can buy in bulk, but the following two charts present an easy way to compare prices at a glance. Also included is a cost comparison chart based on the one in the book, Nutrition: for Health, Fitness, and Sport.
Protein Cost Comparison
Name store US$ per 40g Designer Whey protein powder Pro Sport 1.337 Whey protein powder GNC 1.714 Milk&Egg protein powder Trader Joes 0.760 Milk&Egg protein powder GNC 0.999 MLO Hardbody protein powder Pro Sport 1.146 MetRx MRP VIP 2.144 PerfectRx MRP GNC 1.571 PromaxBar Trader Joes 1.88 Balance Bar Trader Joes 2.54 cottage cheese Trader Joes 1.064 cooked turkey Trader Joes 1.497 BK Broiler chicken sandwich Burger King 4.784 SF Chicken Sandwich Carl's Jr 3.72 BBQ Chicken Sandwich Carl's Jr 4.14 StarKist tuna 4pack Lucky's 0.886 Sirloin Steak Trader Joes 3.50 uncooked frozen chicken breast Trader Joes 1.486 The following information was taken from: http://hit.dozer.com/whey.htm *I added the cost per 40 grams to match the above chart for easy comparison. Quick Protein Cost Comparison Here's the math as I see it: Type Cents/Gram per 40 gr. Whey 1.68 Cents/Gram Protein $.672 Nonfat Milk 1.73 Cents/Gram Protein $.692 Tuna 1.81 Cents/Gram Protein $.724 Powdered Milk 1.84 Cents/Gram Protein $.736 Beef 1.92 Cents/Gram Protein $.768 Soy Protein 2.01 Cents/Gram Protein $.804 Chicken Breast 2.22 Cents/Gram Protein $.888 Egg Whites 2.70 Cents/Gram Protein $1.08 Fat Free Cheese 4.11 Cents/Gram Protein $1.64 From Nutrition: for Health, Fitness, and Sport Modified from p193 (I have used the table in the book to create the one below comparing cost per 40 grams.) Type Cost per 40 grams of protein Powdered Milk $.65 Egg $.65 Turkey Breast $1.05 Skim Milk $1.00 Protein Capsules $6.00 MetRx Bar $3.70 Boost $4.40 Avalanche Power Drink $3.00
From the above three charts it is obvious that there are radically different prices based on where it is purchased and who the manufacturer (in the case of food supplements) is. However, adjusting for those factors, it becomes apparent that Milk Powder is extremely cheap at around $.70 per 40 grams and most name brand supplements are extremely expensive. In general whole foods would be the cheapest form of protein, but buying in bulk over the internet can be as inexpensive. However, since whole foods are more satiable, I would recommend that an athlete use most or all whole food sources. These people should use supplements only for convenience or possibly for post-workout recovery.
Overall Recommendations
Only vegetarians need to worry about the sources of their protein. For all other athletes as long as their diets are predominantly of animal proteins there is no reason to choose one over another. The best and most affordable protein is egg white protein. Athletes in heavy training should take in more protein than the RDA states. However, even they should not go beyond the guidelines that newer research suggests thinking that more protein is going to result in more muscle since excess protein will be excreted in their urine. Several small meals will keep the metabolism high and give the body nutrients throughout the day. If one chooses to use supplements, purchase less expensive brands since the proteins are of equal quality. Varying types of protein may have added health benefits. For example soy has added benefit of lowering the risk of osteoporosis and is full of antioxidants (class notes) and beans have the advantages of providing the body with carbohydrate and fiber. Serious athletes may try using a hydrolysate protein after workouts in order to more quickly repair muscle damage. Finally, the foods selected should be enjoyed and relatively easy to prepare or it will be extremely hard to stick to a dietary plan.
REFRENCES 1 Greenwalt, David. �Honest Whey.� www.thepowerstore.com. Articles Section 2/01/98.Greenwalt*. 2 Colgan, Michael. Optimum Sports Nutrition. New York: Advanced Research Press**, 1993. 3 Williams, Melvin H. Nutrition: For Health, Fitness, and Sport. New York: McGraw-Hill, 1999. 4 Kleiner, Susan M. �The Role Of Meat in an Athlete�s Diet: It�s Effect on Key Macro-and-Micronutrients� SSE#58, Volume 8 (1995), Number 5 Susan M. Kleiner, Ph.D., R.D. 5 Beer, W.H. et al. �Clinical and Nutritional Implications of a Radiation Enteritis�. American Journal of Clinical Nutrition. 1985; 41 p85-91. 6 Smith, J.L. et al. �Increased Ureagenisis and Impaired Nitrogen use During Infusion of a Synthetic Amino Acid Formula�. New England Journal of Medicine. 1982; 306 p1013-8. 7 Calbet JA, et al; �Role of Caloric Content on Gastric Emptying in Humans�. Journal of Physiology(London). 1997 Jan, 498 Pt 2, p553-9. 8 Gaudichon, C. et al. Net Postprandial Utilization of 15N-Labeled Milk Protein Nitrogen is Influenced by Diet Composition in Humans. Journal of Nutrition. 1999; 129. P 890-95. 9 Boirie et al. Slow and Fast Dietary Proteins Differently Modulate Postprandial Protein Accretion. Proceedings of the National Academy of Sciences of the United States of America. 1997; 94(26). p14930-35. 10 Hall et al. �I don�t have the name of this study� Journal of Physiology Aug. 1995. 486(pt 3): p789-94. Also Used in Research www.Healthgate.com - For access to Medline. www.gssiweb.com - For access to online information http://hit.dozer.com/whey.htm http://www.musclememory.com/fogarty/protein.html * This article is on a website for a supplement supplier so it�s information is definitely not guaranteed to be valid, however I used it only for some historical reference and used the question concept from it. ** The company Advanced Research Press is a subsidiary of Twinlabs Inc. a large supplement producer. Thus one must check this books to make sure it�s studies are valid. They are and thus I accept this book as valid even thought there are numerous Twinlab product references inside of it.Back to the Main Page
