Effect of Caloric Restriction and Protein Intake on Metabolism and Anabolic Sensitivity

Can Increased Dietary Protein Prevent the Suppression of Metabolism and Maintain Anabolic Sensitivity of Bone and Skeletal Muscle During Caloric Restriction?

The purpose of this study is to determine if an increased protein intake can attenuate the suppression of metabolic and anabolic hormones during caloric restriction

Preliminary testing Prior to the study start, participants will be weighed and body composition will be determined using calipermetry (7 sites) and bioelectrical impedance. Peak oxygen uptake (VO2peak) will be assessed using an incremental exercise test on a bicycle ergometer. Randomization Participants will proceed through each of the following conditions lasting 5 days: CR-LP: Participants will be restricted to 30 kcal/kg FFM/day and protein intake will be low (0.8 g/kg BW/day). CR-HP: Participants will be restricted to 30 kcal/kg FFM/day and protein intake will be high (1.7 g/kg BW/day). CON: Participants will be in energy balance and consume 1.7 g protein/kg BW/day. Diet Prescription Dietary energy intake will be controlled using clinical products and maltodextrin to meet target energy intakes. Participants will received calcium and Vitamin D supplementation throughout the study. Exercise Prescription During all conditions, participants will conduct daily supervised exercise on a bicycle ergometer at an exercise intensity of 60% VO2peak. Exercise duration will be adjusted individually such that exercise energy expenditure will amount to 15 kcal/kg FFM/day. Additional exercise and intense physical activity will be prohibited. Assessments The following assessments will be conducted prior to the start of each condition as well as upon completion of each condition: body weight and composition (impedance), fasting blood draw for assessment of metabolic and anabolic hormones, resting metabolic rate, aerobic fitness (VO2peak), and questionnaires. Washout Once a participant has completed a study condition, participant will be allowed a washout of at least 14 days to allow protein balance to return to baseline (Hoffer & Forse, 1990). During this time, participants will resume their regular diet and physical activity.

Participants will be provided calcium and vitamin D supplement in order to maintain calcium and Vitamin D intake constant across all study arms

Participants will be provided with maltodextrin to supplement the liquid diet in order to meet caloric needs within each study arm

Perceived hunger will be assessed using 0-100 visual analog scales. In this case, 100 means maximum hunger while 0 means minimal hunger.

Inclusion Criteria: 4 hours/week of purposeful aerobic exercise over the last 3 months Body mass index: 19-25 kg/m2 < 15% body fat Exclusion Criteria: Cardiovascular disease risk factors that would result in greater than low risk Smoking Type I, type II diabetes, or history of high fasting glucose; History of high blood pressure and/or use of medication for hypertension; History of Dyslipidemia, or on lipid-lowering medication; Underlying health condition and/or use of medication that could interfere with any of our study outcomes. History or current diagnosis of a clinical eating disorder Failure to adhere to study protocol

Sports and Exercise Nutrition Laboratory, Department of Nutrition and Health Sciences, Ruth Leverton Hall

Hill JO. Understanding and addressing the epidemic of obesity: an energy balance perspective. Endocr Rev. 2006 Dec;27(7):750-61. doi: 10.1210/er.2006-0032. Epub 2006 Nov 22.

Donnelly JE, Blair SN, Jakicic JM, Manore MM, Rankin JW, Smith BK; American College of Sports Medicine. American College of Sports Medicine Position Stand. Appropriate physical activity intervention strategies for weight loss and prevention of weight regain for adults. Med Sci Sports Exerc. 2009 Feb;41(2):459-71. doi: 10.1249/MSS.0b013e3181949333. Erratum In: Med Sci Sports Exerc. 2009 Jul;41(7):1532.

Weinheimer EM, Sands LP, Campbell WW. A systematic review of the separate and combined effects of energy restriction and exercise on fat-free mass in middle-aged and older adults: implications for sarcopenic obesity. Nutr Rev. 2010 Jul;68(7):375-88. doi: 10.1111/j.1753-4887.2010.00298.x.

Forbes GB. Body fat content influences the body composition response to nutrition and exercise. Ann N Y Acad Sci. 2000 May;904:359-65. doi: 10.1111/j.1749-6632.2000.tb06482.x.

Areta JL, Burke LM, Camera DM, West DW, Crawshay S, Moore DR, Stellingwerff T, Phillips SM, Hawley JA, Coffey VG. Reduced resting skeletal muscle protein synthesis is rescued by resistance exercise and protein ingestion following short-term energy deficit. Am J Physiol Endocrinol Metab. 2014 Apr 15;306(8):E989-97. doi: 10.1152/ajpendo.00590.2013. Epub 2014 Mar 4.

Carbone JW, Pasiakos SM, Vislocky LM, Anderson JM, Rodriguez NR. Effects of short-term energy deficit on muscle protein breakdown and intramuscular proteolysis in normal-weight young adults. Appl Physiol Nutr Metab. 2014 Aug;39(8):960-8. doi: 10.1139/apnm-2013-0433. Epub 2014 Jun 19.

Wasserman DH, Kang L, Ayala JE, Fueger PT, Lee-Young RS. The physiological regulation of glucose flux into muscle in vivo. J Exp Biol. 2011 Jan 15;214(Pt 2):254-62. doi: 10.1242/jeb.048041.

Gault ML, Willems ME. Aging, functional capacity and eccentric exercise training. Aging Dis. 2013 Sep 25;4(6):351-63. doi: 10.14336/AD.2013.0400351.

Dulloo AG, Jacquet J, Montani JP, Schutz Y. How dieting makes the lean fatter: from a perspective of body composition autoregulation through adipostats and proteinstats awaiting discovery. Obes Rev. 2015 Feb;16 Suppl 1:25-35. doi: 10.1111/obr.12253.

Wade GN, Schneider JE, Li HY. Control of fertility by metabolic cues. Am J Physiol. 1996 Jan;270(1 Pt 1):E1-19. doi: 10.1152/ajpendo.1996.270.1.E1.

Loucks AB. Energy balance and body composition in sports and exercise. J Sports Sci. 2004 Jan;22(1):1-14. doi: 10.1080/0264041031000140518.

Misra M, Klibanski A. The neuroendocrine basis of anorexia nervosa and its impact on bone metabolism. Neuroendocrinology. 2011;93(2):65-73. doi: 10.1159/000323771. Epub 2011 Jan 13.

Ihle R, Loucks AB. Dose-response relationships between energy availability and bone turnover in young exercising women. J Bone Miner Res. 2004 Aug;19(8):1231-40. doi: 10.1359/JBMR.040410. Epub 2004 Apr 19.

De Souza MJ, Williams NI. Beyond hypoestrogenism in amenorrheic athletes: energy deficiency as a contributing factor for bone loss. Curr Sports Med Rep. 2005 Feb;4(1):38-44. doi: 10.1007/s11932-005-0029-1.

Rizzoli R, Bianchi ML, Garabedian M, McKay HA, Moreno LA. Maximizing bone mineral mass gain during growth for the prevention of fractures in the adolescents and the elderly. Bone. 2010 Feb;46(2):294-305. doi: 10.1016/j.bone.2009.10.005. Epub 2009 Oct 17.

Pikosky MA, Smith TJ, Grediagin A, Castaneda-Sceppa C, Byerley L, Glickman EL, Young AJ. Increased protein maintains nitrogen balance during exercise-induced energy deficit. Med Sci Sports Exerc. 2008 Mar;40(3):505-12. doi: 10.1249/MSS.0b013e31815f6643.

Pasiakos SM, Margolis LM, McClung JP, Cao JJ, Whigham LD, Combs GF, Young AJ. Whole-body protein turnover response to short-term high-protein diets during weight loss: a randomized controlled trial. Int J Obes (Lond). 2014 Jul;38(7):1015-8. doi: 10.1038/ijo.2013.197. Epub 2013 Oct 29.

Chevalley T, Bonjour JP, Ferrari S, Rizzoli R. High-protein intake enhances the positive impact of physical activity on BMC in prepubertal boys. J Bone Miner Res. 2008 Jan;23(1):131-42. doi: 10.1359/jbmr.070907.

Ross AC, Manson JE, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu RA, Gallagher JC, Gallo RL, Jones G, Kovacs CS, Mayne ST, Rosen CJ, Shapses SA. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011 Jan;96(1):53-8. doi: 10.1210/jc.2010-2704. Epub 2010 Nov 29.