The relation between self-reported body weight and health-related quality of life: a cross-sectional study in Japan.

Background Whilst being obese is associated with increased mortality, less is known about the relationship between body weight and health-related quality of life (HRQOL). We aimed to examine this relationship in the general Japanese population, focusing on both underweight and overweight individuals. Methods We cross sectionally analyzed data from the Health Diary Study, which surveyed health-related behavior in a nationally quasi-representative sample from 2003. HRQOL was measured using the Short Form-8 Health Survey. Body mass index (BMI) was calculated from self-reported height and weight values. We compared differences in HRQOL in people with normal BMI (18.5–24.9) with those with underweight (<18.5), overweight (25–29.9) or obese (≥30) BMIs. Results Among a population-weighted random sample (5387 households), 1857 households (34.5%) agreed to participate. Of the targeted sample population (3658 people), 3477 responded (95.1%). Of 2453 people (age ≥18 years), we analyzed data from 2399 people. After adjusting for age, sex and status of chronic conditions, we found that being overweight was correlated with impaired physical HRQOL [coefficient:−0.96 (95% confidence interval (CI): −1.73, −0.20)] but not with mental HRQOL [coefficient: −0.17 (95% CI: −0.50, 0.95)]. Conclusions Although the differences were small, being overweight was correlated with impaired physical HRQOL but not with mental HRQOL. [ABSTRACT FROM PUBLISHER]