Clustering of health-related behaviors among 18-year-old Australians.

BACKGROUND Few studies among young adults have examined clustering of health behaviors affecting risk for lifestyle diseases. METHODS Smoking, alcohol consumption, physical activity, and diet were examined among Australian 18-year-olds (301 males, 282 females) initially recruited at the age of 9 years from 26 schools. Association analysis was used to recognize behavior clustering. RESULTS Fat intake was greater among male smokers than nonsmokers (36% energy vs 34% energy). Women smokers ate less fiber (14.1 g/day) than did nonsmokers (17.8 g/day). Smoking was significantly related, among males, to unsafe drinking (odds ratio 2.38) and higher fat intake (odds ratio 1.06) and, among females, to unsafe drinking (odds ratio 1.59), lower dietary fiber (odds ratio 0.93), and less physical activity (odds ratio 0.36). Cluster analysis defined separate behavior clusters for men and women with smoking status identifying further subgroups. Smoking, drinking alcohol to excess, and adverse dietary choices clustered among men and women, with physical inactivity also clustering among women. CONCLUSION Smoking among adolescents is an important indicator of behaviors influencing risk for later cardiovascular disease and other medical disorders. Multimodal approaches allowing for gender differences in health-related behaviors are likely to be more successful than targeting a single behavior in this age group.