Optimum Sports Nutrition

QUESTION: How much protein can a bodybuilder or athlete absorb in one meal?

ANSWER: The amount of protein an athlete (or non-athlete) can absorb/metabolize is referred to as the protein threshold and is very specific. The storage capacity of proteins, also called the protein threshold, relates to the maximum amount of protein the human body can process without negative consequences. The protein threshold in humans has been well established in the scientific literature and in current research. One of the most interesting aspects of protein research is that, no matter how much a human weighs, the protein threshold is still the same: 30 grams of elemental protein. For example, in world class powerlifters (who weigh up to 400 pounds) the protein threshold does not exceed 30 grams within a 2-3 hour period. During the time I worked with Mr. Universe Ron Coleman (Editor’s Note: Just for clarification there are two champion bodybuilders named Ron Coleman – one is Mr. Universe and the other is eight-time Mr. Olympia) and the World Powerlifting Federation, my research team experimented with different forms of protein and varying levels of protein intake. Women powerlifters were squatting 650 pounds, and the men were lifting 1000 pounds! This gave us the perfect test subjects to determine the maximum amount of protein a human could metabolize at one time.

Additionally, the Glycemic Research Institute just completed a two million dollar research project on protein thresholding, which reflects the same findings as the study published in the February 2010 issue of the journal of Medicine & Science in Sports & Exercise, in which researchers concluded that there is “Significantly reduced loss of lean body mass with increased protein compared with a normal protein diet in healthy lean athletes.”

The bottom line in protein research reflects the following guidelines:

• In world class bodybuilders, such as Mr. Olympia, who hold huge amounts of muscle mass and low amounts of body fat, regardless of weight or size or calories burned, the 30-gram protein rule does not change. The same holds true with other elite athletes.
• The average non-athlete does not require an intake of 30 grams of protein at one time and can achieve protein homeostasis by ingesting specific forms and amounts of protein throughout the day.
• Based on my research, using proteins at the 30-gram dose in an inappropriate ketogenic formula or product (proteins without carbohydrates) can cause serious problems, including ketosis, elevated liver enzymes, and liver strain.
• Some research suggests that humans ingesting ketogenic proteins (i.e., those without any carbs) and low carb meal replacement products may result in increased body fat levels via elevation of insulin and LPL fat storage in fat cells. Ketogenic protein drinks and meal replacements are contraindicated.
• Protein drinks and protein products that contain only sugar alcohols, certain synthetic sweeteners, and other non-carbohydrate ingredients may hinder healthy protein storage capacity and push the body into ketosis.
• For maximum growth hormone (GH) release, protein drinks should not be consumed near bedtime, as this causes lowered delta-stimulated GH and testosterone production.
• Proteins that contain high glycemic ingredients result in increased body fat levels via elevation of insulin, lipoprotein (LPL), and fat storage in adipose tissue fat cells.

The Doctor’s Prescription

Bodybuilders cannot metabolize more than 30 grams of protein at one time, regardless of athletic ability, energy output, weight or size. In terms of maximum muscle mass, the optimum protocol for an anabolic state is:

• Ingest 30 grams of protein combined with low glycemic carbohydrates, taken every 4 waking hours (not during or near sleep cycles).
• Do not ingest proteins 2 hours prior to sleep (avoids blunting GH).
• Do not ingest ketogenic proteins (protein without carbohydrates).
• Low glycemic carbohydrates are superior in protein drinks (as compared to high glycemic carbohydrates) for increasing lean muscle mass and decreasing body fat.

Scientific References

1. (1) 2010.Glycemic Research Institute; Protein Research Project. INVESTIGATIVE REVIEW, HUMAN IN VIVO CLINICAL TRIALS THE SCIENCE OF TRANSCRIPTION PATHWAYS IN PROTEIN METABOLISM
2. (2) 2010. Medicine & Science in Sports & Exercise: February 2010 - Volume 42 - Issue 2 - pp 326-337. Increased Protein Intake Reduces Lean Body Mass Loss during Weight Loss in Athletes
3. Tang JE, Perco JG, Moore DR, Wilkinson SB, Phillips SM. Resistance training alters the response of fed state mixed muscle protein synthesis in young men. Am J Physiol Regul Integr Comp Physiol. 2008;294:R172-8.
4. Braun B, Brooks GA. Critical importance of controlling energy status to understand the effects of "exercise" on metabolism. Exerc Sport Sci Rev. 2008;36(1):2-4.
5. van Loon LJC, Kruijshoop M, Verhagen H, Saris WHM, Wagenmakers AJM. Ingestion of protein hydrolysate and amino acid–carbohydrate mixtures increases postexercise plasma insulin response in men. J Nutr 2000;130:2508–13.
6. van Loon LJC, Saris WHM, Verhagen H, Wagenmakers AJM. Plasma insulin responses following the ingestion of different amino acid or protein carbohydrate mixtures. Am J Clin Nutr 2000;72:96–105.
7. Willoughby DS, Stout JR, Wilborn CD. Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength. Amino Acids. 2007;32:467-77.
8. Driss T, Vandewalle H, Quievre J, Miller C, Monod H. Effects of external loading on power output in a squat jump on a force platform: a comparison between strength and power athletes and sedentary individuals. J Sports Sci. 2001;19:99-105.
9. Anthony JC, Anthony TG, Kimball SR, Jefferson LS. Signaling pathways involved in translational control of protein synthesis in skeletal muscle by leucine. J Nutr. 2001;131:856-60S.
10. Weigle DS, Breen PA, Matthys CC, et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr. 2005;82:41-8.
11. Layman DK. Protein quantity and quality at levels above the RDA improves adult weight loss. J Am Coll Nutr. 2004;23:631S-6S.
12. Sallinen J, Pakarinen A, Fogelholm M, et al. Dietary intake, serum hormones, muscle mass and strength during strength training in 49 - 73-year-old men. Int J Sports Med. 2007;28:1070-6.
13. Biolo G, Williams BD, Fleming RY, Wolfe RR. Insulin action on muscle protein kinetics and amino acid transport during recovery after resistance exercise. Diabetes 1999;48:949–57.
14. Biolo G, Tipton KD, Klein S, Wolfe RR. An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein. Am J Physiol. 1997;273:E122-9.
15. Bos C, Metges CC, Gaudichon C, et al. Postprandial kinetics of dietary amino acids are the main determinant of their metabolism after soy or milk protein ingestion in humans. J Nutr. 2003;133:1308-15.
16. Bratteby LE, Sandhagen B, Fan H, Samuelson G. A 7-day activity diary for assessment of daily energy expenditure validated by the doubly labelled water method in adolescents. Eur J Clin Nutr. 1997;51:585-91.
17. Edwards RH, Young A, Hosking GP, Jones DA. Human skeletal muscle function: description of tests and normal values. Clin Sci Mol Med. 1977;52:283-90.
18. Friedlander AL, Braun B, Pollack M, et al. Three weeks of caloric restriction alters protein metabolism in normal-weight, young men. Am J Physiol Endocrinol Metab. 2005;289:E446-55.
19. Hagenfeldt L, Wahren J. Experimental studies on the metabolic effects of branched chain amino acids. Acta Chir Scand Suppl. 1980;498:88-92.
20. Hiilloskorpi HK, Pasanen ME, Fogelholm MG, Laukkanen RM, Manttari AT. Use of heart rate to predict energy expenditure from low to high activity levels. Int J Sports Med. 2003;24:332-6.
21. Layman DK, Boileau RA, Erickson DJ, et al. A reduced ratio of dietary carbohydrate to protein improves body composition and blood lipid profiles during weight loss in adult women. J Nutr. 2003;133:411-7.
22. Layman DK, Evans E, Baum JI, Seyler J, Erickson DJ, Boileau RA. Dietary protein and exercise have additive effects on body composition during weight loss in adult women. J Nutr. 2005;135:1903-10.
23. Layman DK, Walker DA. Potential importance of leucine in treatment of obesity and the metabolic syndrome. J Nutr. 2006;136:319S-23S.
24. Leidy HJ, Carnell NS, Mattes RD, Campbell WW. Higher protein intake preserves lean mass and satiety with weight loss in pre-obese and obese women. Obesity. 2007;15:421-9.
25. Livingstone MB, Black AE. Markers of the validity of reported energy intake. J Nutr. 2003;133(Suppl 3):895-920S.
26. McMurray RG, Proctor CR, Wilson WL. Effect of caloric deficit and dietary manipulation on aerobic and anaerobic exercise. Int J Sports Med. 1991;12:167-72.
27. Meckling KA, Sherfey R. A randomized trial of a hypocaloric high-protein diet, with and without exercise, on weight loss, fitness, and markers of the metabolic syndrome in overweight and obese women. Appl Physiol Nutr Metab. 2007;32:743-52.
28. Micklewright D, Alkhatib A, Beneke R. Mechanically versus electro-magnetically braked cycle ergometer: performance and energy cost of the Wingate anaerobic test. Eur J Appl Physiol. 2006;96:748-51.
29. Mourier A, Bigard AX, de Kerviler E, Roger B, Legrand H, Guezennec CY. Combined effects of caloric restriction and branched-chain amino acid supplementation on body composition and exercise performance in elite wrestlers. Int J Sports Med. 1997;18:47-55.
30. Nindl BC, Alemany JA, Kellogg MD, et al. Utility of circulating IGF-I as a biomarker for assessing body composition changes in men during periods of high physical activity superimposed upon energy and sleep restriction. J Appl Physiol. 2007;103:340-6.
31. Noakes M, Keogh JB, Foster PR, Clifton PM. Effect of an energy-restricted, high-protein, low-fat diet relative to a conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women. Am J Clin Nutr. 2005;81:1298-306.
32. Phillips SM. Dietary protein for athletes: from requirements to metabolic advantage. Appl Physiol Nutr Metab. 2006;31:647-54.
33. Quevedo MR, Price GM, Halliday D, Pacy PJ, Millward DJ. Nitrogen homoeostasis in man: diurnal changes in nitrogen excretion, leucine oxidation and whole body leucine kinetics during a reduction from a high to a moderate protein intake. Clin Sci (Lond). 1994;86:185-93.
34. Forslund AH, Hambraeus L, Olsson RM, El Khoury AE, Yu YM, Young VR. The 24-h whole body leucine and urea kinetics at normal and high protein intakes with exercise in healthy adults. Am J Physiol. 1998;275:E310-320.
35. Roberts R, Bickerton AS, Fielding BA, et al. Reduced oxidation of dietary fat after a short term high-carbohydrate diet. Am J Clin Nutr. 2008;87:824-31.
36. Roemmich JN, Sinning WE. Weight loss and wrestling training: effects on nutrition, growth, maturation, body composition, and strength. J Appl Physiol. 1997;82:1751-9.
37. Tipton KD, Wolfe RR. Protein and amino acids for athletes. J Sports Sci. 2004;22:65-79.
38. van Loon LJ, Kruijshoop M, Verhagen H, Saris WH, Wagenmakers AJ. Ingestion of protein hydrolysate and amino acid-carbohydrate mixtures increases postexercise plasma insulin responses in men. J Nutr. 2000;130:2508-13.
39. Walberg JL, Leidy MK, Sturgill DJ, Hinkle DE, Ritchey SJ, Sebolt DR. Macronutrient content of a hypoenergy diet affects nitrogen retention and muscle function in weight lifters. Int J Sports Med. 1988;9(4):261-6.
40. Wilkinson SB, Tarnopolsky MA, Macdonald MJ, MacDonald JR, Armstrong D, Phillips SM. Consumption of fluid skim milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage. Am J Clin Nutr. 2007;85:1031-40.
41. Pallotta JA, Kennedy PJ. Response of plasma insulin and growth hormone to carbohydrate and protein feeding. Metabolism 1968;17:901–8.
42. Rabinowitz D, Merimee TJ, Maffezzoli R, Burgess JA. Patterns of hormonal release after glucose, protein, and glucose plus protein. Lancet 1966;2:454–6.
43. Nuttall FQ, Gannon MC, Wald JL, Ahmed M. Plasma glucose and insulin profiles in normal subjects ingesting diets of varying carbohydrate, fat, and protein content. J Am Coll Nutr 1985;4:437–50.
44. Nuttall FQ, Mooradian AD, Gannon MC, Billington C, Krezowski P. Effect of protein ingestion on the glucose and insulin response to a standardized oral glucose load. Diabetes Care 1984;7:465–70.
45. Floyd JC Jr, Fajans SS, Pek S, Thiffault CA, Knopf RF, Conn JW. Synergistic effect of essential amino acids and glucose upon insulin secretion in man. Diabetes 1970;19:109–15.
46. Floyd JC Jr, Fajans SS, Pek S, Thiffault CA, Knopf RF, Conn JW. Synergistic effect of certain amino acid pairs upon insulin secretion in man. Diabetes 1970;19:102–8.
47. Sener A, Hutton JC, Malaisse WJ. The stimulus-secretion coupling of amino acid-induced insulin release. Synergistic effects of L-glutamine and 2-keto acids upon insulin secretion. Biochim Biophys Acta 1981;677:32–8.
48. McClenaghan NH, Barnett CR, O'Harte FP, Flatt PR. Mechanisms of amino acid-induced insulin secretion from the glucose-responsive BRIN-BD11 pancreatic B-cell line. J Endocrinol 1996;151:349–57.
49. Pipeleers DG, Schuit FC, in't Veld PA, et al. Interplay of nutrients and hormones in the regulation of insulin release. Endocrinology 1985;117:824–33.
50. Xu G, Kwon G, Cruz WS, Marshall CA, McDaniel ML. Metabolic regulation by leucine of translation initiation through the mTOR-signaling pathway by pancreatic beta-cells. Diabetes 2001;50:353–60.
51. Charlton M, Nair KS. Protein metabolism in insulin-dependent diabetes mellitus. J Nutr 1998;128(suppl):S323–7.
52. Matthews DR, Hosker JP, Rudenski AS, Naylor BA, Treacher DF, Turner RC. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia 1985;28:412–9.
53. Wolfe RR, Jahoor F. Recovery of labeled CO2 during the infusion of C-1- vs. C-2-labeled acetate: implications for tracer studies of substrate oxidation. Am J Clin Nutr 1990;51:248–52.
54. Floyd JC Jr, Fajans SS, Conn JW, Thiffault C, Knopf RF, Guntsche E. Secretion of insulin induced by amino acids and glucose in diabetes mellitus. J Clin Endocrinol Metab 1968;28:266–76.
55. Steiner D, Kemmler W, Clark J, et al. The biosynthesis of insulin. In: Steiner D, Freinkel N, eds. Handbook of physiology-endocrinology. Baltimore: Wiliams & Wilkins, 1972:175.
56. Pelletier X, Thouvenot P, Belbraouet S, et al. Effect of egg consumption in healthy volunteers: influence of yolk, white or whole-egg on gastric emptying and on glycemic and hormonal responses. Ann Nutr Metab 1996;40:109–15.
57. Gannon MC, Nuttall FQ, Lane JT, Burmeister LA. Metabolic response to cottage cheese or egg white protein, with or without glucose, in type II diabetic subjects. Metabolism 1992;41:1137–45.

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