NO MAJOR DIFFERENCES IN ENERGY-METABOLISM BETWEEN MATCHED AND UNMATCHED GROUPS OF LARGE-EATING AND SMALL-EATING MEN

Rates of energy expenditure (J/kg fat-free mass (FFM) per min) in norm al weight, 'small-eating' men were compared with those obtained for no rmal weight (n 8) and underweight (n 5) 'large-eating' men. For the ma tched groups of 'large-' and 'small-eaters' there were no differences in resting metabolic rate (RMR) measurements but during controlled dai ly activities there was a small but significant increase (P < 0.05) in energy expenditure in the 'large-eaters'. These results contrast with those obtained for the unmatched groups where energy requirements wer e about 10% (P < 0.01) higher in the underweight 'large-eaters' at res t but were not different during the more energetic (walking) activitie s. However, after adjustment for differences in FFM between these two groups, the resting energy expenditures of the 'large-eaters' (82.54 ( SE 1.51) J/kg FFM per min) were similar to those of the 'small-eaters' (81.87 (SE 1.51) J/kg FFM per min). Oral temperatures were significan tly higher in the matched (0.35-0.65 degrees) and unmatched (0.7-0.9 d egrees) 'large-eaters' both at rest and during the different activitie s, but the thermic effect of food (50 kJ/kg FFM) was one fifth lower ( not significant) in both groups of 'large-eaters'. These results provi de little evidence for any major metabolic differences between groups of 'large-eating' and 'small-eating' men.