Ultraprocessed foods are associated with an increased risk of type 2 diabetes Original paper

The NOVA food classification system covers four food categories according to the level of processing that they have undergone. Group 4 represents ultraprocessed foods made from substances extracted from whole foods (e.g., oils, fats, sugar, starch, and proteins), sourced from components of foods (hydrogenated fats and modified starch), or made in laboratories (flavor enhancers and dyes).

Ultraprocessed foods include preprepared meals, packaged bread, and soft drinks. These low-cost, high-calorie, readily available foods make up an increasing portion of people's diets and may be worsening the global rates of type 2 diabetes. Indeed, observational studies have found an association between some groups of ultraprocessed foods and an increased risk of type 2 diabetes, specifically processed meat and sugar-sweetened beverages, but no previous meta-analyses had assessed the associated risk of type 2 diabetes for ultraprocessed foods as a whole.

This meta-analysis of 18 longitudinal studies in over 1 million participants assessed the association between ultraprocessed food consumption and the risk of type 2 diabetes. The main analysis compared moderate and high ultraprocessed food intake to nonconsumption. Additional analyses were performed to assess the association between the dose response of ultraprocessed foods and the risk of type 2 diabetes.

Of the 18 studies, 13 (72%) found associations between ultraprocessed foods and an increased risk of type 2 diabetes. Compared to nonconsumption, a moderate intake of ultraprocessed foods was associated with a 12% increased risk of type 2 diabetes, and a high consumption was associated with a 31% increased risk.

A moderate intake of ultraprocessed foods was associated with a 12% increased risk of type 2 diabetes in men and an 11% increased risk in women. High intake was associated with a 37% increased risk in men and a 25% increased risk in women.

Consuming ultraprocessed food 2–4 times a week was associated with a 20% increased risk of type 2 diabetes, with a 44% increased risk for consuming ultraprocessed food 5 or more times a week.

Three of the studies in this meta-analysis used the NOVA food system. For these studies, a high intake of ultraprocessed food was associated with a 48% increased risk of type 2 diabetes, but no significant association was found for moderate consumption.