The association between eating frequency (EF) and adiposity in young populations is inconsistent. This cross-sectional study examined associations of EF, meal frequency (MF) and snack frequency (SF) with adiposity measures in US children aged 6-11 years (n 4346) and adolescents aged 12-19 years (n 6338) participating in the National Health and Nutrition Examination Survey 2003-2012. Using data from two 24-h dietary recalls, all eating occasions providing ≥210 kJ of energy were divided into meals or snacks based on contribution to energy intake (≥15 or <15 %), self-report and time (06.00-09.00, 12.00-14.00 and 17.00-20.00 hours or others). When analysed without adjustment for the ratio of reported energy intake:estimated energy requirement (EI:EER), all measures of EF, MF and SF showed inverse or null associations with overweight (BMI≥85th percentile of BMI-for-age) and abdominal obesity (waist circumference≥90th percentile) in both children and adolescents. After adjustment for EI:EER, however, EF and SF, but not MF, showed positive associations in children, irrespective of the definition of meals and snacks. In adolescents, after adjustment for EI:EER, positive associations were observed for EF (abdominal obesity only), SF based on energy contribution and MF based on self-report, whereas there was an inverse association between MF based on energy contribution and overweight. In conclusion, higher SF and EF, but not MF, were associated with higher risks of overweight and abdominal obesity in children, whereas associations varied in adolescents, depending on the definition of meals and snacks. Prospective studies are needed to establish the associations observed here.