World Obesity Day 2023

Obesity is associated with a marked increase in risk of developing chronic diseases such as diabetes, cardiovascular diseases, respiratory complications and certain cancers [1]. It is also associated with a reduction in both life expectancy by up to 10 years in those with severe obesity [2], and quality adjusted life expectancy.

UK estimates indicate 28% of adults in England have obesity with a further 36% being overweight. In addition to this humanistic burden, the annual cost to the UK health service and wider society is estimated to be £6.1 billion and £27 billion respectively [3].

Relatively modest reductions in body weight of between 5% to 10% have been shown to result in clinically meaningful reductions in obesity related complications. Achieving a durable reduction in weight remains, however, a challenge. Recently, NICE has recommended semaglutide for the treatment of obesity in adults with at least one weight-related condition and a body mass index (BMI) of at least 35 kg/m² [4]. Evidence from the STEP 1 randomised double-blind clinical trial, demonstrated that participants taking semaglutide lost on average 12% more of their body weight compared with placebo. A key consideration in NICE’s decision making is that of cost-effectiveness; with the 12% weight loss attributable to semaglutide sufficient to drive a reduction in expected direct healthcare costs and increase in patients’ quality adjusted life expectancy necessary to justify the drug’s acquisition cost.

In addition to conducting health economic evaluations from the patient or cohort perspective, researchers at HEOR have also been working on estimating the wider healthcare system-related consequences associated with managing obesity. For example, while the proportion of excess hospital admissions attributable to obesity are greatest in those with a BMI > 40 kg/m² (42%) at a population, or system, level it is those with a BMI of between 30-35 kg/m² (21% of admission attributable to excess weight [5]) who account for the largest number of excess hospital bed-days, 960,000 versus 566,000 respectively. Across all adults in the UK the annual number of excess hospital bed-days attributable to overweight or obesity is approximately 3 million per year. Given the pressures that healthcare systems currently face attempting to meet demand and reduce waiting lists, a better understanding of the role that effective weight management strategies may have on service capacity is vital.