Underweight among rural Indian adults: burden, and predictors of incidence and recovery.

OBJECTIVE: To study the magnitude and predictors of underweight, incident underweight and recovery from underweight among rural Indian adults. DESIGN: Prospective cohort study. Each participant's BMI was measured in 2008 and 2012 and categorized as underweight (BMI<18·5 kg/m2), normal (BMI=18·5-22·9 kg/m2) or overweight/obese (BMI ≥23·0 kg/m2). Incident underweight was defined as a transition from normal weight or overweight/obese in 2008 to underweight in 2012, and recovery from underweight as a transition from underweight in 2008 to normal weight in 2012. Bivariate and multivariable logistic regression analyses were employed. SETTING: The Birbhum Health and Demographic Surveillance System, West Bengal, India. SUBJECTS: Predominantly rural individuals (n 6732) aged ≥18 years enrolled in 2008 were followed up in 2012. RESULTS: In 2008, the prevalence of underweight was 46·5 %. From 2008 to 2012, 25·8 % of underweight persons transitioned to normal BMI, 12·9 % of normal-weight persons became underweight and 0·1 % of overweight/obese persons became underweight. Multivariable models reveal that people aged 25-49 years, educated and wealthier people, and non-smokers had lower odds of underweight in 2008 and lower odds of incident underweight. Odds of recovery from underweight were lower among people aged ≥36 years and higher among educated (Grade 6 or higher) individuals. CONCLUSIONS: The current study highlights a high incidence of underweight and important risk factors and modifiable predictors of underweight in rural India, which may inform the design of local nutrition interventions.