The growing obesity epidemic

The obesity epidemic is a well recognised phenomenon, both in the specialist literature and in the popular press. In England the proportion of the population classified as being obese increased from roughly 14 per cent in 1993 to 24 per cent 2007. Approximately two per cent of the population is classed as morbidly obese (i.e. – a body mass index greater than 40kg/m2). Amongst the Organisation for Economic Cooperation and Development
(OECD) nations, the UK ranks as fifth in the league table of obesity prevalence. Across England, there is both geographical variation in prevalence and variation according to social class.

The Medical and Economic Significance of Obesity
The link between diabetes and obesity is well established1 and unsurprisingly, the rise in obesity prevalence has been mirrored by that of diabetes. The NHS Information Centre estimates that 2.6 million people in the UK have diabetes and this is predicted to reach four million by 20252. Obesity is also associated with an increased risk in developing other disease states, ranging from hypertension, to cancer.

Overall, obesity shortens lifespan by eight to ten years and as a person’s body mass index increases, their mortality risk also increases.

At present the cost of obesity to the NHS is estimated to be £4.2 billion and the cost to the wider economy is £16 billion. These costs are projected to increase to £10 billion per year by 2050, with the wider costs to society and business reaching £49.9 billion per year, at today’s prices3.

Treatment Strategies
The commonest types of bariatric (weight loss) surgery, are the gastric band and gastric bypass procedures. These tend to be performed laparoscopically (key hole) and when performed by experienced surgeons, the surgery is very safe indeed.

Bariatric surgery is the only clinically effective treatment for morbid obesity. This has been demonstrated in large numbers of clinical studies. One of the most powerful of these studies was the Swedish Obese Subjects study4. This case controlled prospective study looked at over 4000 obese patients, half of whom underwent the best medical treatment for their obesity and half of whom underwent surgery. The surgical group demonstrated greater sustained weight loss, significant improvement of their obesity related comorbidities and also significantly great life expectancy.

Not only has bariatric surgery been evidenced as the only clinically effective treatment of morbid obesity, but it is also cost effective. Most studies indicate that at three years after surgery, health savings are made as a result of the improvement in the patient’s obesity related health5,6. On top of this, there are wider cost savings resulting from increased productivity in the workplace. Health economists gauge the cost effectiveness of treatments by using Quality Adjusted Life Years (QALY). Broadly, this is a method of evaluating the outcomes of health care interventions upon quality of life and life expectancy. The cost per change in QALY can then be assessed. On the whole, NICE will not recommend any treatment which costs more than £20k-£30k per. The incremental cost per QALY for metabolic surgery falls well below this.

Government Strategy

The Government’s Comprehensive Spending Review announced the aim that England was to be the first major country “to reverse the rising tide of obesity and overweight in the population, by ensuring that all individuals are able to maintain a healthy weight.” This aspiration was given a strategic framework with the launch of ‘Healthy Weight, Healthy Lives’7. Many of the clinical guidelines used to deliver this lofty ambition were summarised in the NICE document ‘Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children (CG43)’8.

Using the criteria from this document, patients can be considered for surgical intervention as a first line option where their BMI is greater than 50 kg/m2. Where this is not the case surgical intervention for patients should only be considered where all of the following criteria are met:
• They have a BMI of 40 kg/m2 or more, or between 35 kg/m2 and 40 kg/m2 and other significant disease (for example, type 2 diabetes or high blood pressure) that could be improved if they lost weight.
• All appropriate non-surgical measures have been tried but they have failed to achieve or maintain adequate, clinically beneficial weight loss for at least six months.
• The patient has been receiving or will receive intensive management in a specialist obesity service.
• The patient is generally fit for anaesthesia and surgery.
• The patient commits to the need for long-term follow-up.

Analysis of Hospital Episode Statistics (HES) data for the period 2003/04 to 2009/10 shows that the number of NHS-commissioned metabolic surgery procedures performed for the management of obesity in England has increased year on year from 470 to over 6500 in 2009/20109. However, this figure is equivalent to less than one per cent of eligible adults with morbid obesity in England. Despite the overwhelming evidence supporting the effectiveness of bariatric surgery, Primary Care Trusts throughout the country are not funding surgery for eligible patients.


The NHS is being challenged by the rising prevalence and cost of obesity. Bariatric surgery offers the only clinically effective and the most cost effective way of treating morbid obesity. When performed in specialist centres, it is extremely safe. However, there is a great degree of variation in the provision and accessibility of bariatric surgery across the NHS.


Further reading:

1.Mokdad AH, Ford ES, Bowman BA, Dietz WH, Vinicor F, Bales VS, Marks JS. Prevalence of obesity, diabetes, and obesity-related health risk factors, 2001. JAMA 2003 289:76-79
2.Prescribing for Diabetes in England: 2004/05 to 2009/10. The Health and Social Care Information Centre. 2010
3.Tackling Obesities: Future Choices. UK Government Office for Science. 2007
4.L Sjöström, K Narbro, CD Sjöström, K Karason, B Larsson, H Wedel, T Lystig, M Sullivan, C Bouchard, B Carlsson, C Bengtsson, S Dahlgren, A Gummesson, P Jacobson, J Karlsson, AK Lindroos, Hans Lönroth, I Näslund, T Olbers, K Stenlöf, J Torgerson for the Swedish Obese Subjects Study. Effects of Bariatric Surgery on Mortality in Swedish Obese Subjects. NEJM. 2007 357:741-752
5.PY Cremieux, H Buchwald, SA Shikora, A Ghosh, HE Yang, M Buessing. A Study on the Economic Impact of Bariatric Surgery. American Journal of Managed Care. 2008;14:51-58
6.Buchwald H, Estok, R, Fahrbach kK, Banel D, Jensen MD, Pories WJ, Bantle JP, Sledge I. Weight and Type 2 Diabetes after Bariatric Surgery: Systematic Review and Meta-analysis. American Journal of Medicine. 2009 122: 248-256
7.Healthy Weight, Healthy Lives. A Cross Government Strategy for England.  UK Department Health. 2008
8.Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children CG43. UK National Institute of Clinical Excellence. 2006
9.Dent M, Chrisopoulos S, Mulhall C, Ridler C. Bariatric surgery for obesity. Oxford: National Obesity Observatory, 2010