To investigate possible associations of lifestyle patterns with obesity and fat mass in children.Cross-sectional epidemiological study. Principal component analysis was used to identify lifestyle patterns.Primary schools from four regions in Greece.A total of 2073 schoolchildren (aged 9-13 years).Children in the fourth quartile of the lifestyle pattern combining higher dairy foods with more adequate breakfast consumption were 39·4%, 45·2% and 32·2% less likely to be overweight/obese and in the highest quartile of sum of skinfold thicknesses and fat mass, respectively, than children in the first quartile of this pattern. Similarly, children in the fourth quartile of a lifestyle pattern comprising consumption of high-fibre foods, such as fruits, vegetables and wholegrain products, were 27·4% less likely to be in the highest quartile of sum of skinfold thicknesses than children in the first lifestyle pattern quartile. Finally, children in the fourth quartile of a lifestyle pattern characterized by more time spent on moderate-to-vigorous physical activity and more frequent meals were 38·0%, 26·3% and 29·5% less likely to be overweight, centrally obese and in the highest quartile of fat mass, respectively, than their peers in the first quartile of this lifestyle pattern (all P < 0·05).The current study identified three lifestyle patterns (i.e. one pattern comprising higher dairy consumption with a more adequate breakfast; a second pattern characterized by increased consumption of high-fibre foods; and a third pattern combining higher physical activity levels with more frequent meals), which were all related with lower odds of obesity and/or increased fat mass levels. From a public health perspective, promotion of these patterns among children and their families should be considered as one of the components of any childhood obesity preventive initiative.