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.