title: Reduced rate of energy expenditure as a risk factor for body-weight gain.
abstract: The contribution of reduced energy expenditure to the development of obesity has been a point of controversy. We measured 24-hour energy expenditure (adjusted for body composition, age, and sex), in a respiratory chamber, in 95 southwestern American Indians. Energy expenditure correlated with the rate of change in body weight over a two-year follow-up period (r = -0.39, P less than 0.001). The estimated risk of gaining more than 7.5 kg in body weight was increased fourfold in persons with a low adjusted 24-hour energy expenditure (200 kcal per day below predicted values) as compared with persons with a high 24-hour energy expenditure (200 kcal per day above predicted values; P less than 0.01). In another 126 subjects, the adjusted metabolic rate at rest at the initial visit was also found to predict the gain in body weight over a four-year follow-up period. When the 15 subjects who gained more than 10 kg were compared with the remaining 111 subjects, the initial mean (+/- SD) adjusted metabolic rate at rest was lower in those who gained weight (1694 +/- 103 vs. 1764 +/- 109 kcal per day; P less than 0.02) and increased to 1813 +/- 134 kcal per day (P less than 0.01) after a mean weight gain of 15.7 +/- 5.7 kg. In a group of 94 siblings from 36 families, values for adjusted 24-hour energy expenditure aggregated in families (intraclass correlation = 0.48). We conclude that a low rate of energy expenditure may contribute to the aggregation of obesity in families.
authors.affiliation: Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Ariz. 85016.
authors.forename: E
authors.initials: E
authors.lastname: Ravussin
authors.forename: S
authors.initials: S
authors.lastname: Lillioja
authors.forename: W C
authors.initials: WC
authors.lastname: Knowler
authors.forename: L
authors.initials: L
authors.lastname: Christin
authors.forename: D
authors.initials: D
authors.lastname: Freymond
authors.forename: W G
authors.initials: WG
authors.lastname: Abbott
authors.forename: V
authors.initials: V
authors.lastname: Boyce
authors.forename: B V
authors.initials: BV
authors.lastname: Howard
authors.forename: C
authors.initials: C
authors.lastname: Bogardus
mesh_terms: D000293:Adolescent; D000328:Adult; D001835:Body Weight; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007198:Indians, North American; D008297:Male; D009765:Obesity / Q000209:etiology / Q000235:genetics; D011446:Prospective Studies; D012146:Rest; D012307:Risk Factors