Commentary: The relationship between parity and overweight--a life course perspective

The prevalence of obesity is a rising epidemic of global proportions. No longer is it just a concern for rich countries but increasingly a problem for many developing countries. Obesity is recognized as having both multifarious causes and health-related consequences that are evident from early life and throughout the lifespan. For women in the developed countries child bearing has been identified as a risk factor for weight gain and obesity. Women often report that their obesity had been triggered by pregnancy-as many as 40-50% in one Swedish study. Yet for 30% of the women in the same study pregnancy was associated with a weight loss. In another cross-sectional study from Sweden sociodemographic factors and health behaviours such as education and physical activity had greater effect on BMI than child bearing. In a US national study it was found that after adjusting for a wide range of covariates the associations varied with race and were neither strong nor linear: in comparison with womenwithout children black women living in metropolitan areas with one or two children had increased BMI while white women living in non-metropolitan areas had lower BMI. These cross-sectional studies allude to a complex parity-weight relationship for women with a range of confounding factors that act across the life course with the possibility for further variations for those outside of the developed countries. (excerpt)