Data suggests UK prisons are seeing rapid weight gain behind bars, with obesity rates reportedly as high as 55% and extra‑large uniform orders up 41.75% since 2022
UK prisoners are getting prescribed weight-loss injections, with others getting slimming drug Mounjaro delivered to their cells via drones.
In some UK prisons, the obesity rate is as high as 55% , exceeding the national average by 29 percentage points, compared with 26% of the wider UK population. New data showed that demand for extra-large prisoner uniforms is increasing. As a result, XL uniform orders rose by 41.75% between 2022 and 2024 and the average size surging from 4XL to 6XL.
This comes as category A and high-security prisoners disproportionately drive demand for XL uniforms.
Experts analysed uniform and menu data from the Ministry of Justice, as well as partnering with Dr Shelly Coe, Associate Professor of Nutrition Science at Oxford Brookes University and expert in prison nutrition, to uncover how prison diets and restricted activity are contributing to weight gain behind bars. They also looked at which facilities are seeing the sharpest rises in larger inmates, and the surprising lessons on nutrition that can be learned from prison menus.
According to the new Freedom of Information (FOI) data sourced by the weight loss experts at ZAVA, plus-size prison uniforms soared by 41.74% between 2022 (194) and 2024 (275), with HMP Isle of Wight recording the highest number of XL orders overall (153). The results further found that prisons with the largest inmates serve up greasy weekend fry-ups , including hashbrowns and bacon baps, as well as daily instant noodles, pizza baguettes and pies, with some meals exceeding 2,000 calories alone.
Furthermore, men with waists of 43” or more have a 50% higher mortality risk than those under 35”. At nearly double this benchmark, HMP Whatton in Nottinghamshire and HMP Hollesley Bay in Suffolk recorded the largest average XL waist sizes at 60”.
The data also show the average XL uniform size ordered jumped from 4XL in 2023 to 6XL in 2025, putting UK prisons on track for 8XL uniforms within two years and potentially 10XL by 2030. And, UK prisons see a sharp rise in XL+ prison uniform orders.
As HMP Isle of Wight is the largest orderer of extra-large uniforms, its uniforms included 60” waist trousers and a range of 5XL items, with the overall average size ordered being 5XL and a 49.95” waist. In 2023, the average size across all extra-large prison uniforms ordered was 4XL.
This rose to 5XL in 2024 and 6XL in 2025, an increase of two clothing sizes in just two years. If this trajectory continues, UK prisons could require average extra-large sizes of 7XL by 2026 , and potentially 8XL by 2027.
In second is HMP Frankland, a category A high-security prison, with 109 extra-large uniforms ordered since 2020, including 6XL t-shirts and jackets, as well as 56″ trousers. The prison’s average XL size stands at 4XL, with a 51.47” average waist measurement.
In third is HMP Full Sutton, with 93 extra-large uniforms ordered since 2020. Uniforms ordered by the prison include 8XL t-shirts, sweatshirts and fleeces, as well as 3XL “escapee joggers”, contributing to the prison’s average size of 6XL and average waist measurement of 50 inches.
As part of their study, ZAVA requested sample prison menus from the Ministry of Justice. HMP Wymott, in Lancashire, had the third-highest average waist at 56” and their menu included an array of processed , high-calorie and high-salt foods , such as instant noodles, crisps and cookies with generally poor nutritional quality.
Dr Shelly Coe, Associate Professor of Nutrition Science at Oxford Brookes University, said: “Prisoners in the UK often experience a reduction of autonomy in their lives, with one key aspect being their diet. Although prisoners are presented with menu choices, for example, five options at lunch and dinner, in most cases, they remain restricted to a diet provided by the institution.
“In addition, prisoners experience a higher burden of health issues compared to the general population. Diets are sometimes compromised, yet improvements could lead to better health outcomes.”
In a custodial setting, physical activity may be significantly lower than in the general population. This makes calorie density, processed food burden, and salt intake particularly important health considerations.
Crystal Wyllie, doctor at ZAVA , exlained: “The nutritionally stronger prison menus appear to be higher-effort, with a clear focus on fresh, lower-processed cooking instead of relying on convenience products to fill gaps, particularly at lunch and on weekends. HMP Bure, for example, offers a range of fruit at every meal, two sides of vegetables at dinner, and more nutritionally complete carbohydrates such as wholemeal fusilli and brown rice.
“They also had a regimented, but healthy, structure, such as fresh soup and wholemeal rolls at every lunch or two vegetables at every dinner. They avoided grab bags and instant noodles, ensuring convenience was never prioritised over nutrition.
“At home, applying the same principle by building meals around whole ingredients first, then treating processed or convenient options as occasional additions rather than daily staples, is a great step towards healthier living. The lowest-rated menus, on the other hand, relied on convenience foods such as instant noodles and pastry pies.
“The same thing happens in a lot of our kitchens, when we turn to quick options when in a rush or on the go, plugging the gaps where a proper meal should be. When this becomes routine, these high-calorie, low-satiety choices can drive excess calorie intake and weight gain over time. ”
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