Chronic stress and obesity in adolescents: scientific evidence and methodological issues for epidemiological research.

AIMS: This review describes the role of chronic stress in the development of obesity and available methodologies for the assessment of chronic stress in humans, in particular adolescents, with the aim of developing a feasible methodology to implement in an epidemiological study. DATA SYNTHESIS: Chronic stress seems to be associated with the aetiology of obesity by interacting with both mechanisms of energy intake (increase of appetite and energy intake) and expenditure (decrease of physical activity) and by stimulating visceral fat accumulation in favour of abdominal obesity. However, more research is necessary to unravel the underlying mechanisms of the obesity-inducing effects of chronic stress, especially in adolescents. In addition to experimental research, epidemiological observational studies, in particular cohort studies, are appropriate given their non-intervening character, lower budgetary costs and natural setting. In practice, stress can be assessed by means of either a subjective approach using stressor checklists or interviews, or an objective approach measuring biomarkers of stress. In epidemiological research in adolescents, a combination of both strategies is recommended, with a preference for a general stressor checklist for adolescents and measurement of salivary cortisol, one of the most used and well-characterized biomarkers of stress.
CONCLUSION: This review provides basic evidence for the positive association between chronic stress and obesity, but also points out the need for more research in adolescents to further elucidate the role of chronic stress in the aetiology of obesity in this crucial life period. Good, well-standardized epidemiological surveys could be of great benefit in this research area.