title: Resting energy expenditure and body composition in morbidly obese, obese and control subjects.
abstract: Resting energy expenditure (REE) was investigated by indirect calorimetry in relation to body composition and to different degrees of obesity in order to assess if a defective energy expenditure contributes to extra body fat accumulation. Differences were found between control subjects (group C; BMI 23 +/- 0.5 kg/m2, REE 5890 +/- 218 kJ/day; mean +/- SEM) and obese subjects (group O; BMI 34.2 +/- 0.9 kg/m2, REE 7447 +/- 360 kJ/day; P < 0.0001) and between group C and morbidly obese subjects (group MO; BMI 49.9 +/- 1.6 kg/m2, REE 8330 +/- 360 kJ/day; P < 0.0001); REE was not significantly different between groups O and MO. Body composition data were obtained by means of body impedance analysis. Even though group MO had a fat mass higher than group O, body cell mass, the metabolically active body compartment, was similar in groups O and MO, and this fact may have contributed to the similar REE in the two groups. Multiple regression analysis gave the following equation as the best predictor of REE: REE (kJ/day) = 1591 +/- 49BW + 74BCM - 737G (R2 = 0.88), where BW is body weight, BCM is body cell mass and G is a dummy variable coding group membership (group C = 1; group O = 2; group MO = 3). Thus the analysis showed a negative impact of obesity on REE beyond body composition variables.
authors.affiliation: Cattedra di Clinica Medica B, University of Palermo, Policlinico P. Giaccone, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Verga
authors.forename: S
authors.initials: S
authors.lastname: Buscemi
authors.forename: G
authors.initials: G
authors.lastname: Caimi
mesh_terms: D000328:Adult; D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001834:Body Water / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D009767:Obesity, Morbid / Q000503:physiopathology*; D012044:Regression Analysis