Food insufficiency, Supplemental Nutrition Assistance Program status, and variability in weight and body composition: Longitudinal analysis of the National Health and Aging Trends Study Cohort 2012-2021

BACKGROUND: The impact of food insecurity and food assistance programs on long-term body weight and composition is unclear. OBJECTIVES: The aim of the study was to investigate the associations between baseline and duration of food insufficiency (FI), the Supplemental Nutrition Assistance Program (SNAP) status, and variability in weight, BMI, and waist circumference (WC). METHODS: Data from 3897 eligible Medicare beneficiaries aged ≥ 65 y recruited in the National Health and Aging Trends Study (2012-2021) were analyzed. At baseline, SNAP status was assessed. With repeated measurements over follow-up, baseline FI status, years with FI experience (nFI), 3 variability metrics for weight, BMI, and WC [i.e. SD, coefficient of variation (CV), root mean squared error (RMSE)] and 4 patterns (stable, loss, gain and cycling) were defined. Partial proportional-odds generalized ordered logit models and multinomial logistic regression models were fit to investigate the association between FI status, nFI, and SNAP status and quartiles of variability metrics and patterns, respectively. RESULTS: The median (IQR) follow-up years was 8 (4, 9). Per 1-unit increase in the nFI, older adults had significantly higher variability in BMI (OR: 1.08-1.10), weight (OR: 1.14-1.15), and waist circumference (OR: 1.11-1.27) by SD, CV, and RMSE. SNAP participants did not differ from eligible nonparticipants in any variability metrics. Older adults with FI at baseline were 2.72 times (95% CI: 1.32, 5.58) more likely to gain weight. Relative risk of weight loss (RRR: 1.29; 95% CI: 1.06, 1.56), gain (RRR: 1.34; 95% CI: 1.09, 1.65), or cycling (RRR: 1.27; 95% CI: 1.04, 1.21) increased per 1-unit increase in nFI. SNAP participants did not differ in BMI, weight, or WC patterns from eligible nonparticipants. CONCLUSIONS: Recurring food insecurity is associated with variability in older adults' weight and body composition. Additional interventions beyond SNAP are needed to prevent food insecurity and instability in body weight and composition.