Factors associated with maintenance of body mass index in the Jackson Heart Study: A prospective cohort study secondary analysis

The purpose of this study was to compare the relationship of diet quality, physical activity, and environmental factors with body mass index (BMI) maintenance in African American adults. We analyzed data from 4041 participants in the Jackson Heart Study, a prospective cohort study based in Jackson, Mississippi. Exposures were baseline American Heart Association diet quality score, American Heart Association physical activity categories, the built environment, the food environment, and neighborhood safety. The outcome was weight maintenance or loss (no BMI increase ≥ 1.0 kg/m2) versus weight gain (BMI increased ≥ 1.0 kg/m2) over a mean of 5.0 years. We found that 63% of participants maintained or lost weight and 37% gained weight. In multivariable analyses, ideal diet quality was associated with a 6% greater likelihood of BMI maintenance (incidence rate ratio [IRR] 1.06, 95% confidence interval [CI]: 1.03, 1.10). Living in an unsafe neighborhood was associated with a 2% lower likelihood of BMI maintenance (IRR 0.98, 95% CI: 0.96, 0.99), as was poor built environment (IRR 0.98, 95% CI: 0.97, 0.998). Physical activity and poor food environment were not associated with BMI maintenance. In conclusion, among African American adults in Jackson, Mississippi, high quality diet was the strongest factor associated with BMI maintenance.