Energy balance and body composition in cancer patients.

Energy balance and body composition were studied in 10 cancer patients to investigate the interrelationship between energy expenditure and energy intake in the development of cancer cachexia. These data were com pared to the findings in control patients of similar age with diseases affecting physical activities to about the same extent. The measurements of energy expenditure and intake were repeated when possible during progression of the malignant disease. Body composition in a larger group of cancer patients (n = 29) was compared to data from a group of healthy subjects within the same age range (n = 164). The cancer patients were below normal in body weight and body cell mass. Body fat was reduced in women with cancer. Energy intake (mean, 1270 kcal/ day), although varying greatly, was not significantly differ ent from the intake in the controls (mean, 1470 kcal/day). Both the daily energy expenditure (mean, 2020 kcal/24 hr) and the resting metabolic rate (mean, 1630 kcal/24 hr) were significantly greater in the cancer patients than they were in the controls (mean, 1420 and 1170 kcal/24 hr, respectively). Parallel to exacerbation of the disease and reduced energy intake, the energy expenditure and the resting metabolic rate increased in relation to body cell mass in two patients. After curative surgery both intake and expenditure of energy returned to normal levels in one patient. For a more accurate interpretation of the higher daily energy expenditure and resting metabolic rate found in the cancer patients, the influences of body weight, body cell mass, and height were ruled out. The results suggest that one of the reasons for the develop ment of cancer cachexia is an increasing resting metabo lic rate and daily energy expenditure.