Background: Obesity is a global health problem. Eating breakfast maybe associated with a lower risk of obesity in adolescents; scarce evidence is available in our country about risk of obesity associated to the frequency of daily meals or shortened sleep. Objective: To evaluate the association among daily meals and sleeping schedules and risk of adiposity and obesity in Chilean adolescents. Subjects and methods: In a cross-sectional study, 290 adolescents (12-19 y), attending to a public school in San Antonio city Chile, were evaluated for nutritional status, daily meal schedule and sleep. Results: Obesity was greater in females consuming <= 3 meals/day vs >= 4 meals/day (9.4% vs 0.7%; OR= 7.6 IC95%: 1.8-44.0); also in males (17.7% vs 2.6%; OR= 9.8 IC 95% : 2.9-41.3). Abdominal circumference was higher in females consuming <= 3 meals/day than those with >= 4 meals/day (83.8 +/- 10.9 vs 73.3 +/- 6.6 cm; (p< 0.05), and also in males (81.2 +/- 9.5 vs 75.5 +/- 6.3 cm; p< 0.05); 38.8% of males with <= 3 meals/day had increased body fat vs 7.2% in those consuming >= 4 meals/day (OR= 10.5 IC95%: 3.3-35.1). Males sleeping < 9h/d exhibited > BMI: 22.8 +/- 3.9 vs 21.5 +/- 3.9 Kg/m(2) (p< 0.05). Multivariate analysis showed the number of daily meals as the only factor associated with obesity. Conclusions: In these Chilean adolescents, low amount of daily meals is the main factor associated to obesity, to adiposity and to abdominal circumference, and few hours of sleep/day only for males.