Body mass index and weight change attempts among adult women - The Norwegian Women and Cancer Study

Background: Based on concern about the widespread increase in being overwei ght and obesity along with a substantial demand for leanness, we wanted to estimate body mass index (BMI) and the prevalence of weight change attempts in a population-based sample of Norwegian women. Furthermore, we wanted to examine how weight loss attempts are related to BMI and to age, socioecono mic status, reproductive factors, lifestyle and diet, Methods: A nationwide , cross-sectional study applying a mailed questionnaire was used. Out of a random sample of 20,000 women aged 45-69 years 10,249 women participated, R esults: Based on self-reported data, the mean BMI was 24.6 kg m(-2) and 40% of the women had a BMI of greater than or equal to 25 kg m(-2). More than 50% of the women were trying to lose weight and weight loss attempts were v ery strongly associated with BMI, Age, education, income, smoking status an d perception of diet's importance to health were also significant predictor s of weight loss attempts. The effect of age, education and income on weigh t loss attempts was modified by the level of BMI, Women trying to lose weig ht reported a different diet than those not trying to lose weight, irrespec tive of BMI. Conclusion: A large proportion of middle-aged women are trying to lose weight. BMI is predominant in explaining weight loss attempts, Aft er adjusting for BMI, age, lifestyle and socioeconomic status also contribu te to explaining weight loss attempts.