BackgroundObesity is a major risk factor for many cancers. Glucagon-like peptide-1 receptor agonists (GLP-1RA) have emerged as highly effective agents for weight loss. There is a lack of published modelling studies describing the broader implications of GLP-1RA-induced weight loss on cancer incidence.MethodsA Markov state-transition model was devised to evaluate the impact of GLP-1RA-induced weight loss on future cancer incidence in adults. Contemporary data on weight distribution, cancer incidence, and body mass index (BMI)-associated cancer risk were integrated into the model. Two scenarios were assessed, GLP-1RAs were made available to all people with obesity (BMI>30) or only those with severe obesity (BMI>35). New cancer cases were simulated over a decade.ResultsOur simulation within a closed cohort indicated that GLP-1RA-induced weight loss would lead to a marked decrease in cancer cases over 10 years in adults. If GLP-1RAs were made available for all people with obesity and 50 % of people with obesity moved into a lower BMI category, there was a simulated reduction in cumulative cancer cases of 21,443. If access to GLP-1RAs was restricted to people with severe obesity and 50 % of people with severe obesity moved into a lower BMI category, there was a simulated reduction in cumulative cancer cases of 7476. This effect was greatest for uterine, kidney, liver and colon cancer.ConclusionTargeted weight control measures using GLP-1RAs could reduce new cancer cases. Based on our models, the potential risk of thyroid cancer is balanced by a reduction in other cancer types. This modelling study shows for the first time that implementing effective weight loss programmes could enhance the health of the population over the next decade through a reduction in cancer cases.