A new study reveals that worldwide, male prisoners are slimmer than men in the general population, and female prisoners are more obese than the general population – apart from in the UK.

Conducted by Dr. Katharine Herbert, Department of Public Health, University of Oxford, UK and her team, the study is the first systematic analysis of diet, exercise, overweight, and obesity in prison populations worldwide.

Researchers have the opportunity to address major public health risk factors by studying vulnerable populations like prisoners. Not taking advantage of this opportunity translates into a high cost to society.

Non-communicable disease (NCDs) is a medical condition or disease which is non-infectious and non-transmissable between persons. NCDs are increasingly seen as a global health crisis due to the increasing prevalence of diseases, such as

Poor diet, alcohol, lack of exercise, and smoking are all risk identified risk factors for NCDs.

NCDs are currently responsible for 3 in 5 deaths worldwide. Even though studies have evaluated the prevalence of alcohol and tobacco use by prisoners, no study has been conducted evaluating diet and physical activity.

The researchers examined 31 studies, including over 60,000 prisoners in 884 institutions in 15 countries and found that female prisoners were 18% more likely to be obese than the general female population in the USA, as were Australian female prisoners.

In addition, they found male prisoners were between 13% to 67% less likely to be obese than non-imprisoned males.

UK female prisoners were less likely to be obese than non-imprisoned UK women, although the researchers are unsure as to why.

Although physical activity data was only available for the UK and Australia, it nevertheless showed that in comparison with Australian prisoners and the generally UK population, UK prisoners tended to be less likely to achieve the recommended guidelines for physical activity. Australian prisoners, however, were more likely to engage in over 150 mins of moderate exercise each week, which was more than that for the same sex of the general population.

According to the researchers:

“This difference cannot be attributed purely to a cultural difference; something must be inherent in the structure of the prison environment that enables Australian prisoners to exercise.

The analysis of prisoner diet showed that while male diets in high-income countries provide an appropriate calorie intake, female diets provided a substantial excess of total energy. The evidence suggests that female prisoners are simply supplied with a diet designed for males.”

The researchers conclude:

Studies in Australia and Japan describe how the prison regime can favorably influence NCD risk factors, thus showing that improvement of prison regimes and environments in such a way that favors health promotion and reduces modifiable risk factors is possible. The challenge remains to ensure that every prison provides a healthy diet and ample opportunities for physical activity.”

In an association comment, Dr Frank W. Arnold, Director of research, Oxford Wound Healing Unit, Medical rapporteur for Freedom from Torture and Helen Bamber Foundation, and Co-founder, Medical Justice Network, explained:

“In countries where the frequency and duration of incarceration are rising, the incidence and consequences of non-communicable diseases will inevitably increase in parallel with an aging population in jail. An increase in the incidence of non-communicable diseases will magnify problems associated with management of disorders such as diabetes and epilepsy, and prisoners could be accused (rightly or wrongly) of manipulating their treatment for nefarious ends, potentially resulting in dangerous neglect.

Ultimately, the most important potentially modifiable factor in prisoners’ environment is imprisonment itself. Since much international variation exists in the rates at which people are incarcerated and the reasons why this happens, there seems to be substantial scope for beneficial reform. But such reform is a political question, not a medical one.”

Written By Grace Rattue