Obesity treatment in the UK risks becoming a two-tier system

Treatment for obesity in the UK could become a two-tier system where the most vulnerable patients miss out altogether, obesity experts from King's College London and the Obesity Management Collaborative (OMC-UK) have warned. They stated that strict eligibility criteria means that only a small number of people will have access to the weight loss drug tirzepatide (Mounjaro) on the NHS, with those able to afford it paying privately for treatment.

The researchers argue, in an editorial published in the British Journal of General Practice (BJGP), that this gap creates a two-tier treatment system, where the ability to self-fund determines who receives care.

"The planned rollout of Mounjaro risks creating a two-tier system in obesity treatment. Unless we adjust how eligibility is defined and how services are delivered, the planned roll-out of Mounjaro risks worsening health inequalities, where ability to self-fund determines access to treatment and those with the greatest need are less likely to qualify for treatment,” explained lead author, Dr Laurence Dobbie, NIHR Academic Clinical Fellow in General Practice at King's College London. “Current eligibility criteria require multiple diagnosed qualifying criteria, yet the very conditions used to gatekeep access to Mounjaro are frequently underdiagnosed in women, people from minority ethnic communities, those from low income and patients with severe mental illness. The underdiagnosis is well-documented and regional variation in NHS commissioning creates a postcode lottery. We should recognise underdiagnosis explicitly in obesity pathways, prioritise our patients at the highest clinical need, and scale culturally adapted wrap-around support so access is based on need, not means or location."

Obesity is a global health crisis linked to serious conditions such as heart disease, type 2 diabetes and cancer. The NHS's phased rollout of tirzepatide, has been welcomed as an important step in tackling the problem. Recent data suggests that more than one and a half million people in the UK are accessing these new medications privately. By contrast, NHS provision is expected to reach only around 200,000 patients in the first three years.

The current NHS criteria for access to Mounjaro require patients to have a BMI of 40 or above combined with several additional health conditions such as diabetes, high blood pressure or heart disease. While this approach does provide some access to effective obesity treatment, it excludes many people who are at serious risk but do not meet all of these requirements. The researchers warn that these rules risk widening existing health inequalities.

"Obesity is a complex, chronic disease that demands equitable access to treatment for all who need it, not just those who can afford it. The current approach risks entrenching a two-tier system where wealth, rather than medical need, determines access to care,” added Professor Barbara McGowan, professor in endocrinology and diabetes at King's College London. “We urgently need a more inclusive, fair and scalable model that ensures effective treatments are accessible across all communities, especially those already facing systemic barriers to health care.”

The opinion piece calls for changes to improve fairness and equity. These include changing who qualifies for support, setting up clearer routes to accessing care that take ethnicity and underdiagnosis into account, accelerating the national rollout, and expanding digital health services to reach patients in areas where specialist services are limited.

The authors also stress that access to medication must go hand-in-hand with broader public health measures, including policies to improve diets, address food insecurity and ensure healthier urban environments.

"Obesity care should not depend on postcode or the ability to self-fund. Current criteria risk excluding high-need patients because qualifying conditions are often under-diagnosed in the very groups who face the greatest barriers to care,” added Professor Mariam Molokhia, professor in epidemiology and primary care at King's College London. “For equitable delivery of care, it is important to recognize underdiagnosis in eligibility criteria, prioritize severe obesity and those with the highest clinical needs, and provide culturally adapted behavioural support."

The researchers conclude that without urgent changes to policy, inequalities in obesity care will persist and worsen for future generations.

The findings were reported in the paper, 'Tirzepatide and the NHS: are we creating a two-tier obesity treatment system?', published in the British Journal of General Practice. To access this paper, please click here