Physical activity but not energy expenditure is reduced in obese adolescents: a case-control study,,

Abstract

Obese adolescents are less physically active than are normal-weight adolescents, but physical activity-related energy expenditure is not significantly different between groups. The data suggest that physical activity is not necessarily equivalent to the energy costs of activity.

Does physical activity equally predict gain in fat mass among obese and nonobese young adults?

“…25 The results from that study also suggest that PA might not necessarily be equivalent to the energy cost of activity. 25 However, cross-sectional associations only imply causality, but not its direction and only if they are not explained by chance, bias or confounding. Furthermore, it is unknown whether metabolic determinants, PAEE and subcomponents of PA equally predict gain in BW and FM among obese and normal weight individuals.…”

“…25 All participants were reinvited for 'follow up' measurements 4 years later. Thirty of the 36 eligible individuals agreed to participate in follow-up measurements.…”

“…25,26 Resting metabolic rate (RMR) was measured by indirect calorimetry in the morning after an overnight fast and after 30 min of supine rest. Resting metabolic rate was calculated according to De and Weir.…”

“…25 Urine samples were analysed in duplicate with an isotoperatio mass spectrometer (Optima; VG Isogas Ltd, Micromass, Manchester, UK). CO 2 production was converted to TEE using an energy equivalent based on the individual food quotient (FQ) calculated from the macronutrient composition of the diet as described by Black et al, 29 assuming the respiratory quotient (RQ) to be equal to FQ.…”

“…A 7-day precoded food record 30 was used for recording of food intake. 25 Physical activity energy expenditure was calculated as TEE Â 0.9 minus RMR, with correction for a 10% dietinduced theromgenesis. 31 Minute-by-minute body movement (i.e.…”