Functional status and emotional well-being, dietary intake, and physical activity of severely obese subjects.

OBJECTIVE: Analyze functional status and emotional well-being, energy and nutrient intake, and physical activity in sibling pairs raised together in the same family.
DESIGN: One sibling classified as severely obese (body mass index > or = 35) and the other sibling as normal weight (body mass index < or = 27).
SUBJECTS: From January 1994 through December 1996 at the Cardiovascular Genetics Research Clinic of the University of Utah School of Medicine, 145 sibling pairs (n = 290) were selected from a population-based, family history database or a hospital-based, very-low-energy weight-loss program. STATISTICAL ANALYSIS PERFORMED: Repeated-measures analysis of variance tested for differences between severely obese and normal-weight siblings.
RESULTS: All functional status and emotional well-being scores (poorer perceived health) were significantly lower in severely obese siblings compared with normal-weight siblings. The severely obese siblings had a higher percentage dietary fat intake (3% higher) and total energy intake (more than 350 kcal higher), and lower weight-adjusted total energy intake (almost 10 kcal/kg lower) and activity energy expenditure (3.5 kcal/kg lower), compared with normal-weight siblings. Thus, environmental influences such as energy and nutrient intake and physical activity are highly related to severe obesity. APPLICATIONS: Previously shared environment of severely obese and normal-weight siblings raises questions about whether strong environmental influences or genetic predisposition account for the differences in sibling weight. When counseling individuals or families with a history of severe obesity, dietetics practitioners should be familiar with the potential for strong genetic factors and related environmental influences. In addition, dietitians should be prepared to offer a flexible approach to physical exercise as well as provide additional behavioral support.