To investigate the relationship between physical activity and diet with depressive symptoms, and their potential role in the prevention and treatment

Depressive symptoms are a widespread and debilitating aspect of mental illness, with depression recently being reported as the leading cause of disability worldwide1 and mental illness accounting for 32.4% of total years lived with a disability2. People with mental illness are at an elevated risk of physical health complications, such as cardiovascular and metabolic disease, with serious mental illness being associated with a life expectancy 20 years below the population average3. As services struggle to effectively manage comorbid mental and physical comorbid conditions6, and just 11% of the total healthcare budget afforded to mental health in the UK5, cost-effective methods are required to reduce the mental health burden its associated physical health risks. Lifestyle approaches could be an important, versatile tool for promoting both physical and mental health.