The researchers assessed the participants’ dietary intake (typically using a Food Frequency Questionnaire), adherence to different vegetarian diets, and intake of plant foods (both healthy and unhealthy).

Type 2 diabetes risk was 32% lower with a lacto-ovo vegetarian diet (i.e., a vegetarian diet that includes dairy and eggs) than with a nonvegetarian diet. Type 2 diabetes risk was also 25% lower in the participants with the highest adherence to a healthy plant-based diet (emphasizing legumes, vegetables, and whole grains) than in the participants with the lowest adherence.

A dose-response analysis indicated that the higher the adherence to a healthy plant-based diet, the lower the type 2 diabetes risk.

Higher adherence to an unhealthy plant-based diet (including desserts, refined grains, and sugar-sweetened beverages) was associated with a 27% higher risk of type 2 diabetes, but the finding wasn’t statistically significant.

Eat more plants, lower your type 2 diabetes risk? Original paper