Generational differences in associations between health conditions in young women and BMI categories

The objective of this study was to investigate whether the associations between BMI categories and the age-specific prevalence of health conditions common in young women differed across generations.

Data were from the Australian Longitudinal Study on Women's Health for participants born between 1973 and 1978 or 1989 and 1995 and recruited in 1996 and 2013, respectively. Women were included if they reported their weight and height at waves conducted when they were aged 18 to 23, 22 to 27, and 25 to 30 years. Outcomes were self-rated health, the prevalence of common conditions, menstrual symptoms, and pregnancy complications. Odds ratios (ORs) were estimated using logistic regression models with generalized estimating equations to account for repeated measures.

For fair or poor self-rated health, the ORs were higher for women in the underweight range (OR 1.51, 95% CI: 1.30-1.74) or the overweight range (OR 1.47, 95% CI: 1.34-1.60), were highest for women with obesity (OR 3.04, 95% CI: 2.76-3.35) compared with women with normal weight, and were higher for the more recent cohort (OR 1.50, 95% CI: 1.38-1.63). This same pattern was apparent for all outcomes.

The health impacts of increasing BMI are not lessened in more recent generations. This evidence can be used to promote the benefits of normal BMI for young women.