The incidence of type 2 diabetes has risen globally, in parallel with the obesity epidemic and environments promoting a sedentary lifestyle and low-quality diet. There has been scrutiny of ultra-processed foods (UPFs) as a driver of type 2 diabetes, underscored by their increasing availability and intake worldwide, across countries of all incomes. This narrative review addresses the accumulated evidence from investigations of the trends in UPF consumption and the relationship with type 2 diabetes incidence. Hypotheses for why UPFs may be causally implicated in the initiation and progression of weight gain and suboptimal blood glucose levels are varied. There is also uncertainty and debate about whether detrimental effects of UPFs could be owing to additives and other features of industrial processing, independent of established dietary risk factors, namely added sugar, sodium, saturated fat and low fibre content. However, these current research gaps are addressable with rigorous research and coordinated efforts across nutrition-science domains
for example, the strengths of longitudinal cohort studies can be leveraged to refine the characterisation of key UPF subcategories within the enormous and diverse category of UPFs and ultra-processed beverages, and to identify high-risk patterns of intake that are related to the development of chronic-disease outcomes. The notable advantages of dietary intervention studies are the critical gains in the reliability of dietary assessments, and isolating the effects of individual UPF additives and features through carefully formulated diets. Research improving our understanding of the modifiable food environment, the diet's causal drivers of weight gain and suboptimal cardiometabolic health, and the interactions among them, can be used to meaningfully shift the food supply for large-scale improvements in health. Thus, although the global market share of UPFs seems to outpace the research on its detrimental health effects, leaving the scientific community with the responsibility of generating proof, there may still be promising opportunities to reduce the burden of type 2 diabetes.