EFFECT OF SEDENTARY ACTIVITIES ON RESTING METABOLIC-RATE

We examined the effect of television viewing on resting metabolic rate (RMR) in a cohort of 9 obese and 18 nonobese girls aged 10.4 +/- 1.1 y. RMR was measured while girls watched television, read, or sat quiet ly for 15 min. Movement was assessed by using activity monitors and a manual count of movements observed on a videotape. Absolute RMR was gr eater for the obese girls, but no significant treatment effect existed for absolute RMR within either group. Although measured activity did not differ, observed movements were greater when the girls were sittin g quietly. Total observed and measured movements were significantly co rrelated with the CV of the minute-by-minute RMR. These results sugges t that television viewing does not alter RMR. Although children appear to fidget more when sitting quietly than when they read or watch tele vision, fidgeting appears to affect the minute-to-minute variation of RMR rather than the level of resting energy expenditure.