Development of overweight and obesity in mid-age women from the Australian Longitudinal on Women Health Study (#177)
Aim: Obesity is at epidemic proportions worldwide. Therefore the aim was to investigate the relationship between diet quality, physical activity, and the development of overweight and obesity in mid-aged women during six years of follow-up after adjustment for baseline weight.
Methods: A prospective cohort from the Australian Longitudinal on Women Health Study
(ALSWH) [n= 3,403, age range 47.6-55.8 years, normal weight (25 > BMI ≥ 18.5 kg/m2) at baseline], who were disease free. Diet quality was measure by the Australian Recommended Food Score (ARFS), physical activity and smoking status were reported at baseline. BMI was calculated (kg/m2) from self-reported height and weight (2001 and 2007). Women were categorised as overweight (25 ≥ BMI < 30kg/m2) or obese (BMI ≥ 30) at follow-up. Logistic regression used to assess the relationship between the variables and becoming overweight/ obese and repeated in sub-sample with plausible total energy intakes (n = 1,107).
Results: The respective six year incidence of overweight and obesity was 18.5% and 1.1%. Diet quality was not related to the risk of becoming overweight/obese. Those women classified as being moderately physical active were less likely to become overweight/obese compared to those inactive (OR=0.45; CI: 0.26, 0.79)(p=0.005). Women who had quit smoking at baseline were more likely to become overweight/obese (OR=1.47; CI: 1.01, 2.13)(p=0.043) and those with higher baseline weight were also more likely to become overweight/obese at follow-up (OR=1.14; CI: 1.10, 1.18)(p<0.001).
Conclusion: Mid-age is associated with substantial weight gain and high incidence of overweight/obesity. Public health interventions are needed to help prevent weight gain at this life stage. Those with excessive weight gain, especially smokers or those who have quit smoking may need targeted interventions. While this study does not support improving diet quality as a strategy to prevent weight gain, it does suggest that improving diet quality is not associated with weight gain.