Grant: Doctoral: Vanier Canada Graduate Scholarships

Diversity in a diet has long been considered essential to healthy eating and many dietary guidelines have incorporated recommendations on dietary diversity to reduce the risk of chronic diseases such as type 2 diabetes (T2D). However, some dietary guidelines have minimized and potentially undermined the importance of dietary diversity by reducing the number of food groups relevant to a healthy diet. Moreover, most of the diet quality measures do not capture dietary diversity, while quality and diversity are not completely alike despite a positive correlation, and diversity may be linked to disease prevention independent of quality. To date, most of the existing knowledge on dietary diversity comes from developing countries, where dietary diversity is an approach to address nutritional inadequacy, and thus is not a measure of diet quality in the context of a sufficient amount of food. And, in higher-income settings, research on dietary diversity rarely looks at the risk of T2D. Even less is known about diversity within food groups separate from the diversity of total diet. Moreover, although we know from previous studies that gender/sex, socio-economic status, and obesity can affect both dietary intakes and development of diabetes, it is still unclear whether mentioned factors can alter the degree of a potential association between dietary diversity and T2D. The underlying mechanism linking dietary diversity to T2D also remained to be elucidated, despite some studies separately showing the beneficial effect of dietary diversity on gut microbes and the protective effect of gut microbes against T2D. Therefore, this project aims to use data from multiple European countries to answer three main questions: (1) Do greater diversity across total foods and within food groups (e.g. vegetables) reduce the risk of T2D?; (2) Is this relationship altered by gender/sex, socio-economic status, and obesity?; and (3) Do gut microbes have a role in linking diversity to diabetes?.