Systematic review into obesity and weight gain within male prisons.

OBJECTIVES: To review current studies on obesity and weight within male prisoners. Including assessment of factors which influence obesity and weight change during imprisonment.

STUDY DESIGN: A systematic review.

METHODS: The systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. A literature search was conducted using defined exclusion and inclusion criteria for relevant studies published between 2000 and 2016.

RESULTS: The findings show the prevalence rates of obesity for prisoners range from 8.1% to 55.6%, with prison population often having lower levels of obesity than the general population. The findings are inconclusive into those factors that influence weight change and obesity during imprisonment, though potential factors and their mechanisms are highlighted.

CONCLUSION: Current literature highlights the complex relationship between imprisonment and weight. A significant amount of evidence exists to suggest that obesity levels are similar or lower in prison population compared to the general population. Future research might explore more intensively the various factors influencing prisoners' weight change within prison, including food, diet, activity levels and other relevant factors in relation to weight change, using both quantitative and qualitative methods.