Objective: American adults gain on average 1-2 lb/year. Sociodemographic and lifestyle factors have been shown to influence body weight. This influence has not yet been well characterized among blacks and low-income Americans, who are at high risk for obesity and related diseases.
Methods: Included in the study were 12,261 blacks and 6,307 whites, 40-69 years old, who participate in the Southern Community Cohort Study, had no history of diabetes, cardiovascular disease, or cancer, and reported ≥2 body weight measures, one at baseline and another during follow-up. Mixed model was used to evaluate 5-year weight change in relation to baseline factors and changes in factors during follow-up. Analyses were conducted among all subjects and stratified by sex and race and baseline obesity status. Differences in 5-year weight change>1 lb with FDR-p<0.10 were considered significant.
Results: During follow-up (median: 6 years; range: 0.5-15 years), participants gained 2.5 lb/year. After mutual adjustments, greater 5-year weight gain was seen among men (+1.61 lb) than women and associated with getting married (+1.67 lb), quitting smoking (+4.72 lb), and transition to menopause (+1.98 lb). The association for marital status change was most evident among white men (+5.80 lb) and the association for quitting smoking was most evident among subjects with baseline BMI>35 (+8.95 lb). Diet and other lifestyle factors (e.g., physical activity) overall contributed modestly to 5-year weight change in this population, although associations were observed for per serving increase in greens and beans among white women (-4.61 lb) and dairy among white men (+3.30 lb) and Healthy Eating Index among subjects with BMI>35 (-2.02 lb per 10 points increase).
Conclusion: Changes in smoking, marriage, and menopause status contribute to body weight change among low-income Americans. Certain dietary factors are also related to weight change, but the association may vary by sex, race, and obesity status.
J. Yang: None. X. Shu: None. D. Yu: None.
