OBJECTIVES : Trends in body weight continue to increase globally, with the prevalence of obesity more than doubling in the US over the last 30 years. Obesity is associated with elevated risks of cardiovascular disease, type 2 diabetes and cancer, burdening both healthcare systems and individuals. The objective of this study was to estimate potential healthcare cost savings associated with weight loss in the US obese adult population.

METHODS : Body mass index (BMI, kg/m²) and prevalence of obesity (BMI≥30) in people aged at least 18 years was characterized using 2015/16 NHANES data. Published medical care cost savings associated with 5%, 10%, 15% or 20% reductions in BMI were applied as a function of current BMI and scaled to a population level using 2017/18 US census data. Subgroup analyses were conducted for people with type 2 diabetes (assumed 90% of all people with diabetes) or categorised as severely obese (BMI≥40). All costs were reported in 2018 USD.

RESULTS : Of 5,662 adults with BMI recorded in NHANES, 39.7% and 7.9% had BMI ≥30 and ≥40, respectively. Prevalence of obesity was higher in people with diabetes (58.0% and 14.7%, respectively), who accounted for 14.1% of adults in NHANES. At a population level, annual savings ($Bn) of 209.6, 320.3, 377.5 and 413.4 were estimated for BMI reductions of 5%, 10%, 15% and 20%, respectively, in over 100 million obese adults. Annual savings ($Bn) of 37.2–119.2 were estimated for the type 2 diabetic subgroup and 166.2–337.0 in the severely obese subgroup alone.

CONCLUSIONS : Further to the wide-ranging health benefits of maintaining normal body weight, even modest improvements in BMI could significantly reduce the financial burden of obesity in the US. Effective strategies to treat obesity may be best aimed at more overweight individuals for whom greatest changes in medical costs may be achieved.