A range of individual nutrients and foods have been suggested to increase obesity risk in childhood, but the evidence is inconsistent. Dietary patterns that summarise the whole diet may, however, be more informative. The aim of the present paper was to systematically review the current evidence pertaining to overall dietary patterns in childhood and later obesity risk. Studies eligible for review identified childhood dietary patterns using an empirical method, i.e. principal components analysis, factor analysis or reduced rank regression, and reported their prospective associations with an obesity-related outcome. Literature searches identified 166 studies and of these, seven met the eligibility criteria. Despite differences between studies, a common dietary pattern was identified in all seven studies that was high in energy-dense, high-fat and low-fibre foods. The quality of studies varied, however; the four studies reporting positive associations between this type of dietary pattern and later obesity risk were of consistently higher quality than those reporting null associations. The balance of evidence from this systematic review indicates that dietary patterns that are high in energy-dense, high-fat and low-fibre foods predispose young people to later overweight and obesity. It also highlights that examining multiple dietary factors within a dietary pattern may better explain obesity risk than individual nutrients or foods. However, more prospective studies are needed and dietary pattern research requires greater rigour and focus, to further clarify the role of dietary factors in the aetiology of obesity and inform future interventions.Dietary patterns: Obesity: Children: Adolescents: Cohort studies: Review A range of specific nutrients and foods have been suggested as important dietary determinants of obesity in childhood and adolescence, including but not limited to, fruit and vegetables (1) , fibre (2) , fat (3) , fast food (4) and sugary drinks (5) . However, with the exception of sugary drinks, where the evidence is increasingly clear (5) , the specific dietary risk factors for obesity in young people remain a matter of debate.It is plausible that the overall dietary pattern may better explain obesity risk than individual nutrients or foods. Dietary patterns can summarise the combined and potentially synergistic effects of a repertoire of foods contributing to usual dietary intake in a defined population. Many food and nutrient intakes are strongly correlated or colinear, providing the basis for dietary patterns. This colinearity is partly due to the natural composition of the human diet, which has evolved over millennia by way of biology, ecology and culture. Moreover, where food is abundant, as in most western societies, dietary patterns may also be shaped by wider determinants, such as food environments (6) and psychology, e.g. social norms (7) and hedonic hunger (8) . While epidemiologists may wish to separate the effects of individual exposures, e.g. foods and nutrients, the correlated nature of di...