Effects of a physical activity and nutrition program for seniors on body mass index and waist-to-hip ratio: a randomised controlled trial.

Abstract

OBJECTIVE: To investigate whether a home-based program, physical activity and nutrition for seniors (PANS), made positive changes to central obesity, measured by body mass index (BMI) and waist-to-hip ratio (WHR). METHODS: A 6-month randomised controlled trial was conducted targeting overweight and sedentary older adults aged 60 to 70 years residing in low to medium socio-economic suburbs within metropolitan Perth. Intervention participants (n=248) received mailed materials and telephone/email support to improve nutrition and physical activity levels. Controls (n=230) received small incentives to complete baseline and post-intervention questionnaires. Both groups reported anthropometric measures following specific written instructions. Generalised estimating equation models were used to assess repeated outcomes of BMI and WHR over both time points. RESULTS: 176 intervention and 199 controls (response rate 78.5%) with complete data were available for analysis. After controlling for demographic and other confounding factors, the intervention group demonstrated a small (0.02) but significant reduction in WHR (p=0.03) compared to controls, no apparent change in BMI was evident for both groups. The 0.02 reduction in mean WHR corresponded to a 2.11 cm decrease in waist circumference for a typical hip circumference. CONCLUSION: PANS appears to improve the WHR of participants. Changes in BMI might require a longer term intervention to take effect, and/or a follow-up study to confirm its sustainability.