PRINCIPAL INVESTIGATOR(S ): Paul C. Rambaut , Malcom C. Smith, and Harry 0. 



Wheeler 



EXPERIMENT TITLE/NUMBER : Nutritional Studies 



PROGRAM/MISSION : Apollo 



CLASSIFICATION : Human 



DISCIPLINE(S) : Environmental health 



OBJECTIVES : To study musculoskeletal changes, clinical disorders in space due 

 to imbalance between bone formation and resorption, inflight weight loss, and 

 inflight caloric intake. 



PROTOCOL : The menu and caloric intake of the astronauts were carefully 

 monitored. Food was analyzed for N, fat, carbohydrate, crude fiber, Ca, P, 

 Fe, Na , K, and Mg . Body volume was measured by stereophotogrammetry , and 

 total body water was calculated by K-42 dilution. Analysis was made of urine, 

 blood, and fecal samples to study metabolic balance. 



EQUIPMENT : Stereophotogrammetry apparatus. 



RESULTS : Intake of potassium was monitored in Apollo for input and output. 

 Less K was lost during flight than pref light. In Apollo 17, water consumption 

 was lower during flight and urine output was lower. The insensible loss was 

 900-1200 cc/day, the same as preflight. There was a negative balance in 

 phosphorus, and nitrogen during flight. A diminished nitrogen retention 

 indicated a general musculoskeletal deterioration. Potassium retention 

 inflight was less than that established during the control study. There was a 

 mean body weight loss of 3-9 kg, and water loss of 1.77 liters. It was found 

 that fat loss occurred rather than lean body loss. In Apollo 15, there were 

 pronounced electrolyte anomalies. They may have been associated with inflight 

 cardiac arrhythmias and postflight changes in exercise performance and 

 cardiovascular responses. 



CONCLUSIONS : Estimates of body composition changes from metabolic balance 

 data provide no evidence for diminished caloric requirements during a flight. 

 Measurements of bone density and metabolic balance confirm a tendency toward 

 loss of skeletal tissue in weightlessness. No evidence exists that any 

 inflight metabolic anomaly, including hypokalemia, was induced by marginal or 

 deficient nutrient intakes. In general, the Apollo crewmen were well 

 nourished and exhibited normal gastroenterological functions, although 

 appetite was somewhat diminished and the organoleptic response to food was 

 somewhat modified. 



PUBLICATIONS : 240, 287, 357, 435, 438, 453, 483, 484, 487 



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