¹School of Human Movement Studies, University of Queensland, Brisbane, Australia

²Research Institute for Gender and Health, University of Newcastle, Newcastle, Australia

³School of Psychology, University of Queensland, Brisbane, Australia

⁴School of Population Health, University of Queensland, Brisbane, Australia

Correspondence to: W J Brown, School of Human Movement Studies, University of Queensland, Brisbane, QLD 4072, Australia. wbrown@hms.uq.edu.au

OBJECTIVE: To explore relationships between body mass index (BMI, kg/m²) and indicators of health and well-being in young Australian women.

DESIGN: Population based cohort study¾baseline cross sectional data.

SUBJECTS: 14,779 women aged 18-23 who participated in the baseline survey of the Australian Longitudinal Study on Women's Health in 1996.

MEASUREMENTS: Self-reported height, weight, medical conditions, symptoms and SF-36.

RESULTS: The majority of women (68%) had a BMI in the range 18.5-<25; 12% had a BMI <18.5; 14% had a BMI in the range 25-<30 and 6% had a BMI 30. After adjustment for area of residence, age, education, smoking and exercise, women in the highest BMI category (30) were more likely to report hypertension, asthma, headaches, back pain, sleeping difficulties, irregular periods, and more visits to their medical practitioner. They were also more likely to have given birth at least once, and less likely to report 'low iron'. Women with low BMI (<18.5) were more likely to report irregular periods and 'low iron'. Mean scores on the SF-36 sub-scales for physical functioning, general health and vitality were highest for women with BMI in the range 18.5-25.

CONCLUSION: Acknowledging the limits of the cross-sectional nature of the data, the results show that the deleterious effects of overweight can be seen at a comparatively young age, and that BMI <25 is associated with fewer indicators of morbidity in young women. However, as BMI lt;18.5 is associated with low iron and irregular periods, care should be taken when developing strategies to prevent overweight in young women, not to encourage women with healthy weight to strive for a lower BMI.

International Journal of Obesity (2000) 24, 1360-1368

body mass index; morbidity; symptoms; well-being