Obesity is a major risk factor for type 2 diabetes, but its impact on type 1 diabetes (T1D) has been relatively unexplored. Generally, T1D is more common in the underweight or normal-weight population. However, recent evidence suggests that teenage obesity is also a major risk factor for T1D in later life. T1D predominantly develops in children or young adults before the age of 40 years and accounts for about 5% to 10% of all diabetes cases. As developed countries are in the midst of the childhood obesity epidemic, the increased risk for T1D will create a significant healthcare burden for these countries.

According to a June 2022 study conducted by Zucker and colleagues and published in ‘Diabetologia’, obesity was significantly positively associated with an increased risk of T1D (hazard ratio of 2.05 in obese compared to the non-obese teenagers). This was a large observational study that included 1.4 million Israeli teenagers ages 16 to 19 years from 1996 to 2016. The risk of T1D rose in tandem with body weight and those who were overweight had a 54% greater risk, while in the obese the risk doubled compared to normal-weight teens. The potential mechanism for this association is unclear, but common genetic or immunological pathways could be a possible explanation.

T1D and obesity are significant global health burdens. GlobalData epidemiologists forecast that there were 600,000 diagnosed prevalent cases of T1D that were also obese in the eight major markets (8MM: US, France, Germany, Italy, Spain, UK, Japan and Canada) in 2022. This will increase to 650,000 diagnosed prevalent cases in the 8MM in 2029. The increase in the number of T1D cases who were obese can be attributed to the projected increase in the population in the respective markets during the forecast period and the high prevalence of obesity in these markets. According to the US Centers for Disease Control and Prevention, 20% of children and adolescents in the US were obese in 2020.    

T1D is more severe than type 2 diabetes, and if the condition is left untreated, high levels of blood sugar can damage major organs, such as the heart, blood vessels, nerves, eyes and kidneys. Thus, T1D has an immense impact on the physical, psychological and social well-being of patients. Considering the substantial economic and health burden associated with T1D, more research is needed to understand the risk associated with obesity. It is also important to establish effective public health strategies to control the obesity epidemic.