Background: Adolescence is a transitional life phase that is associated with heightened risk for two major health conditions- obesity and mental health problems. Given the established co-morbidity of obesity and depression, on avenue that warrants further exploration is the association between obesogenic risk and obesity in the expression and maintenance of depressive symptoms. 

Aim: The aim of the current systematic review was to identify and evaluate the empirical literature reporting the relationships between obesogenic risk factors (physical activity, sedentary behaviour, diet and weight status) and depression in adolescents. 

Method: Articles were identified through CINAHL, MEDLINE, Health Source: Nursing and Academic Edition, PsychARTICLES and PsychINFO. The search was limited to peer-reviewed English papers published between January 2002 and April 2013. Eligibility criteria included samples of typically developing adolescents aged 10-19 years, and that examined obesity risk factors and depression. Studies were excluded if they focused on particular groups and/or were pilot of feasibility studies. This resulted in 24 studies eligible for review.

Results: Twelve of the reviewed studies were longitudinal and 12 were cross-sectional. Relationships were found between lack of physical exercise, heightened sedentary behaviour, poor diet quality, obese or overweight and depression in adolescence. Findings however should be interpreted with caution as data typically come from non-representative samples with sub-optimal study design. 

Conclusion: Limitations aside, the finding that obesity risk factors are associated to depression in adolescents have potential to inform clinical practice guidelines of adolescent health, aligning with public health strategies to reduce overweight and obesity and also depression.