Background: We aimed to assess for the first time in a single cohort whether annual weight and waist circumference (WC) change has varied over time.
Methods: We analysed 3351 participants of the population-based Australian Diabetes, Obesity and Lifestyle cohort study (AusDiab) who attended each of three AusDiab surveys (1 – 1999/2000; 2 – 2004/2005; 3 – 2011/2012), and had complete measures of weight, WC and covariates. Generalized linear mixed models with random effects were used to compare annual weight and WC change between AusDiab 1 and 2 (Period 1) with that between AusDiab 2 and 3 (Period 2). Models were adjusted for age, sex, education status, area-level disadvantage, ethnicity, body mass index, diabetes status, and smoking status.
Results: Mean weight and WC increased in both Periods. Annual weight gain in Period 2 was 0.11 kg/year (95% CI 0.06–0.15) less than in Period 1. Improvement in annual weight gain between the two periods was not seen for those with greatest area-level disadvantage, or in men over the age of 55. In contrast, the annual WC increase in Period 2 was greater than in Period 1 (0.07 cm/year, 95% CI 0.01–0.12). In those with least area-level disadvantage only, annual WC gain was less in Period 2 than Period 1.
Conclusions: Between 2004/5–2011/2, Australian adults in a national study continued to gain weight, but more slowly than 1999/2000–2004/5. While some obesity prevention strategies may be working, they do not appear to be affecting WC, older men or those in more disadvantaged groups.