Obesity: identification, assessment and management

Resource impact summary report

The guideline covers assessing overweight and obesity in adults, children and young people. It does not cover children aged under 2 or women during pregnancy. The guideline updates and replaces the recommendations on identification and classification of overweight and obesity in NICE’s guidelines on:

• Obesity: identification, assessment and management (2014) NICE guideline CG189.
• BMI: preventing ill health and premature death in Black, Asian and other minority ethnic groups (2013) NICE guideline PH46.

The surgical interventions update amends and replaces the recommendations on surgical interventions in NICE’s guideline on obesity: identification, assessment and management (2014).

The number of people living with overweight or obesity is estimated to be around 64,000 per 100,000 population (Health Survey for England, 2021: Data tables). Government estimates indicate that the current costs of obesity in the UK are £6 billion to the NHS, expected to rise to £9.7 billion by 2050 (Department of Health and Social Care’s press release on new obesity treatments and technology).

Most of the recommendations in the updated guideline reinforce best practice, and where best practice currently takes place, additional resources to implement will not be required. Some of the guideline areas and recommendations may represent a change to current local practice. Where a change is required to current practice, this may require additional resources to implement, which may be significant at a local level. Benefits derived from the change in practice may help mitigate any additional costs.

Due to a lack of robust data on current practice and the variation across organisations and services, the size of the resource impact will need to be determined at a local level.

Depending on current local practice, recommendations/areas which may require additional resources and result in additional costs include:

• Using lower BMI thresholds for overweight and obesity for people from a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background (recommendation 1.2.8).

While existing guidelines already make reference to recognising that the populations in recommendation 1.2.8 are at higher risk at lower BMI levels, this is the first time that these adults will be classed as living with overweight or obesity at a lower BMI. This will result in an estimated 1.5 million additional adults living with overweight or obesity by 2026/27 after adjusting for expected population growth and could result in additional demand for NHS weight management services of around 24,000 adults per year.

• Reducing barriers to access bariatric surgery (recommendation 1.10.1).

Bariatric surgery is already recommended for adults with BMI 35 km/m² to 39.9 km/m² with a health condition that could be improved by weight loss and adults with BMI 40+ kg/m² in the previous NICE guideline. However, the surgical interventions update makes the additional criteria less restrictive. It removes the requirement that ‘all appropriate non-surgical measures have been tried but the person has not achieved or maintained adequate, clinically beneficial weight loss’ replacing it with ‘taking previous weight loss attempts into account’. This should make bariatric surgery available to more adults. However, while it is expected that more adults will be referred for bariatric surgery, it is not clear that the number of adults choosing bariatric surgery will increase significantly as a result of this guidance and this will depend on local factors affecting capacity to perform bariatric surgeries.

The National Obesity Audit (NHS Digital) shows that in 2017/18 to 2019/20, between 5,600 to 6,100 bariatric surgeries were performed each year. This figure dropped in 2020/21 to 2,000 surgeries as a result of the COVID-19 pandemic and while the number of surgeries increased to 4,000 in 2021/22, they have still not recovered to pre-pandemic levels. Preliminary data for 2022/23 shows that in the first 2 quarters of the period, 2,100 surgeries were performed which can be projected to 4,200 for the year, which is still significantly lower than pre-pandemic levels.

Therefore, it is possible that more people will be referred to bariatric surgery services and wait times for surgery may increase. The guidance recommends that adults waiting for surgery could be eligible for semaglutide in line with the recommendations of the NICE technology appraisal guidance on semaglutide.

The projected eligible population for bariatric surgery is 4.4 million people based on around 37 million people living with overweight or obesity by 2026/27. However, we know that some people do not use NHS services for weight loss, with apps, fitness clubs, diet and exercise, gym memberships and ‘no weight loss’ much more common than use of NHS weight loss services. Bariatric surgery is an invasive procedure that requires life-long follow-up with only a very small proportion of people who meet the eligibility criteria tending to be referred. In addition, not all of those referred will subsequently choose to undergo surgery.

It is difficult to project any likely impact of this guidance on the number of people choosing to have bariatric surgery or even to estimate how long it will take for surgical activity to reach pre-pandemic levels. The resource impact template allows users to amend the uptake figures to reflect local plans and estimates.

Implementing the updated guideline may:

• Reduce the incidence of type 2 diabetes, cardiovascular disease and other weight-related health conditions in these populations in the long term as they have earlier access to NHS weight management services.
• Reduce health-based inequalities for people from a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background.

These benefits may also provide some savings to offset some of the potential costs identified above. These benefits are not included within the local resource impact template provided alongside this summary report to allow modelling of the potential costs and benefits associated with implementing the updated guideline recommendations. This is because the benefits are unlikely to occur within the first 5 years.

Weight management services are commissioned by integrated care systems and local authorities. Bariatric surgery is commissioned by integrated care boards. Providers of weight management services are NHS hospital trusts, community providers and local authorities.