Objectives: To examine sociodemographic factors associated with long-term adult weight gain and current general and central adiposity in women.
Design: Cross-sectional analysis based on data from the Malmö Diet and Cancer prospective cohort Study (MDCS), Sweden.
Subjects: 5464 women aged 45-73 y, who participated in the MDCS between 1994 and 1996.
Measurements: Weight change was defined as the difference between measured weight and recalled weight at age 20. Body composition was estimated from bioelectrical impedance analysis. Waist circumference and waist-hip ratio (WHR) were indicators of central obesity. Sociodemographic factors studied included reproductive, lifestyle and socioeconomic characteristics obtained from a questionnaire.
Results: At current age 13% of all women were obese (BMI>/=30), and nearly one-third had a body fat content of >33%. Since age 20, the majority of women (77%) had gained more than 10% of their initial weight. On average, the mean weight change was 12.6+/-10.0 kg during adult life. Age-adjusted group mean comparisons identified a number of significant sociodemographic variables predicting past weight gain and current obesity. In multivariate analysis, significant independent correlates of weight gain were: age, initial small body size, high parity, early menarche, non-use of hormone therapy, low self-rated health, non-smoking, no consumption of alcohol, sedentary leisure activity, past change in diet, retirement, low education, low socioeconomic status, and low socioeconomic status of origin. Many of the same variables were independently associated with current waist circumference, WHR, and percentage body fat.
Conclusions: Large weight gain during adult life and a high rate of overweight were observed in this group of Swedish women. Many sociodemographic characteristics were associated with long-term weight gain and recent obesity indices. Initial BMI, smoking, age, physical activity and early socioeconomic status accounted for most of the explained variance in weight change. The findings indicate the importance of identifying environmental determinants of both weight gain and attained fatness, as well as fat distribution.