INTRODUCTION:Adolescence is a period marked by physical, psychological, emotional and social changes, resulting in higher vulnerability of youngsters to external factors influences on lifestyle choices in dimensions like food consumption, physical activity level, and sedentary activities practices, among others. OBJECTIVE: The objective of the present study was to identify associations among lifestyle (referring to diet quality, physical activity level, and sedentary activities practice), nutritional status and socioeconomic level in a sample representative at populational level of adolescents living in the municipality of Sao Paulo, using data from three editions of the Sao Paulo Health Survey (ISA-Capital). METHODOLOGY: The adolescents' nutritional status was based in estimation of the Body Mass Index, considering cutoff points proposed by the World Health Organization. The quality of adolescents' food consumption patterns was estimated using the Healthy Eating Index Revised, the physical activity level was expressed in minutes of physical activities per week, and the practice of sedentary activities was measured in hours of activities performed whilst seated per day.Logistic regressions were estimated to identify associations among dimensions of lifestyle (diet quality, physical activity during leisure, and sedentary activity practices), nutritional status, and socioeconomic status of adolescents. RESULTS: The present study identified positive association among diet quality, skin color, educational attainment and physical activity leve, whilst there was negative association with ownership of computer in the household.Overweight was inversely associated with educational attainment and diet quality of the adolescent; on the other hand, it was positively associated with sedentarism and adoption of practices of controlling food consumption for weight loss. The adoption of healthy lifestyle was positively associated with adolescents' age, skin color and educational attainment, and negatively associated with computer ownership. Adolescents with worst diet quality and insufficient physical activity level, as well as adolescents in families with lower income level, had higher probability of hospitalizations; whilst adolescents with companion had higher probability of hospitalizations. Considering household health care expenditures, there was reduction of expenditures according to adolescents' age, as well as according to improvements in diet quality. On the other hand, adoption of practices of food consumption control for losing weight, computer ownership and higher income level were positively associated with health care expenditures. CONCLUSION: Indicators of healthy lifestyle referring to diet quality and physical activity practice, as well as nutritional status, showed association with demographic and socioeconomic characteristics of the individual and the household environment. The adoption of unhealthy lifestyle resulted in higher propensity to hospitalizations and higher health care expenditures; therefore, it ...