|Racette, Susan - Washington University|
|Rochon, James - Duke Clinical Research Institute|
|Uhrich, Mary - Washington University|
|Villareal, Dennis - Baylor College Of Medicine|
|Das, Sai - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Fontana, Luigi - Washington University|
|Bhapkar, Manjushri - Duke University|
|Martin, Corby - Pennington Biomedical Research Center|
|Redman, Leanne - Pennington Biomedical Research Center|
|Fuss, Paul - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Roberts, Susan - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Kraus, William - Duke University|
Submitted to: Medicine and Science in Sports and Exercise
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2017
Publication Date: 11/1/2017
Citation: Racette, S.B., Rochon, J., Uhrich, M.L., Villareal, D.T., Das, S.K., Fontana, L., Bhapkar, M., Martin, C.K., Redman, L.M., Fuss, P.J., Roberts, S.B., Kraus, W.E. 2017. Effects of two years of calorie restriction on aerobic capacity and muscle strength. Medicine and Science in Sports and Exercise. 49(11):2240-2249. https://doi.org/10.1249/MSS.0000000000001353.
DOI: https://doi.org/10.1249/MSS.0000000000001353 Interpretive Summary: Calorie restriction is the only intervention to improve lifespan in animal species. This study investigated the effects of 2 years calorie restriction in adult humans, in a unique protocol randomizing non-obese men and women to an assessment-only control or to 25% calorie restriction. The regimen did not adversely influence fitness (aerobic capacity) or strength, providing further support for calorie restriction being a healthy dietary intervention to support healthy aging without adverse side effects for fitness and strength.
Technical Abstract: Purpose: Calorie restriction (CR) improves health span and delays age-related diseases in many species. The multicenter Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) study was the first randomized controlled trial of CR in nonobese humans. The aim of this investigation was to determine the effects of CR on VO(2max) and muscle strength in the CALERIE trial. Methods: Healthy, normal-weight, and mildly overweight women and men (n = 218, mean +/- SE age = 37.9 +/- 0.5 yr) were randomized to 25% CR or an ad libitum (AL) control condition in a 2:1 allocation (143 CR, 75 AL). VO(2max) was determined with an incremental treadmill test; the strength of the knee flexors and extensors was assessed by dynamometry at baseline, 1 yr, and 2 yr. Results: The CR group achieved an average 11.9% +/- 0.7% CR during the 2-yr intervention. Body weight decreased in CR (-7.7 +/- 0.4 kg), but not AL (+0.2 +/- 0.5 kg). Absolute VO(2max) (Lmin^-1) decreased at 1 and 2 yr with CR, whereas VO(2max) expressed relative to body mass increased at both time points (1 yr. +2.2 +/- 0.4; 2 yr. +1.9 +/- 0.5 mL x kg^-1 min^-1) and relative to AL. The CR group increased their treadmill test time and workload at 1 and 2 yr. Strength results in CR were similar, with decreases in absolute flexor and extensor strength, but increases when expressed relative to body mass. No changes were observed for VO(2max) expressed relative to lean body mass or leg lean mass. Conclusions: Two years of modest CR without a structured exercise component did not appear to compromise aerobic capacity in healthy nonobese adults. The clinical implications of the observed changes in VO(2max) and muscle strength will be important to explore in future studies.