PROTEIN REQUIREMENT AS A FUNCTION OF CALORIE INTAKE AND WORK LOAD.
Abstract
Fourteen volunteers, aged 18-23, consumed liquid diets containing 35 calories/kg. body weight/day; 6 received 1.2 (diet I) and 8 received 0.4 (diet II) gm protein/kg. body weight/day. Half of each diet group walked 1 hour twice daily on motordriven treadmills set at 4 mph and 11.5% grades; the other half served as absolute controls. The three 12-day work phases, following an 8-day training phase, were preceded by a 12-day control period and a 4-day period of adjustment to diets. Working subjects showed decreases in 24 hour creatinine and alpha-amino N excretion, suggesting the possibility of protein anabolism during work. Mechanical efficiencies were higher in all working subjects than in comparably trained subjects on U.S. military diets. Diet II working subjects also demonstrated clinical paroxysmal tachycardias and numerous ventricular extrasystoles after 24 days of work. Data from this pilot study suggest a peak protein requirement of 1.7 fm./kg. body weight/day prior to completion of adaptation with a decrease to 1.3 gm. as adaptation to work load sets in. The data suggest the desirability of limiting diet calories and providing abundant protein if optimum physiological adaptation to work loads, maximum mechanical efficiency and optimum protein retention for the development and maintenance of muscle size and strength are to be attained. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1963
- Accession Number
- AD0426468
Entities
People
- Donald M. Watkin
Organizations
- Massachusetts Institute of Technology