We aimed to systematically review current literature on temporal relationships between psychological factors and subsequent adiposity gain and obesity onset within childhood/adolescence. Databases were searched for longitudinal, population-based studies assessing psychological predictors and adiposity-related outcomes ≥ 1 year later. Study characteristics were synthesised into descriptive Tables and quality evaluated. Fifteen papers met inclusion criteria. Predictors broadly related to psychological symptoms or self-esteem. Evidence was mixed as to whether depressive symptoms and other negative emotional states may increase risk for adiposity gain and obesity onset within adolescence. There was some evidence for low self-esteem predicting obesity onset. Among obese adolescents, depressive symptoms exacerbated obesity, while physical appearance self-esteem exerted gender-specific adiposity changes. The literature had substantial limitations and inconsistencies. This review provides some support for psychological components in obesity prevention/intervention programs as part of a multifactorial approach to tackling childhood obesity. Further good-quality longitudinal research would strengthen the sparse literature and clarify inconsistencies.