Aims: To identify the most important determinants associated with not developing Type 2 diabetes in women considered to be at very high risk. Methods: Between 1995 and 2014, we followed 402 women from the E3N cohort study who were considered to be at very high risk of Type 2 diabetes based on the D.E.S.I.R. score. We then computed a classification and regression tree model to identify, among a large set of risk factors, the top risk factors associated with not having Type 2 diabetes at the end of the follow-up. Results: During follow-up, 117 women (29%) were diagnosed with Type 2 diabetes, while 285 (71%) were still free of the disease in 2014. A low Western dietary pattern score was the top characteristic associated with not developing Type 2 diabetes, as only 20% of the women at very high risk in the E3N study with that characteristic developed Type 2 diabetes (compared with 29% overall). In women with a moderate or high Western dietary pattern score, the most important characteristic associated with not developing Type 2 diabetes was a high total dietary antioxidant capacity, as only 26% of these women ultimately developed Type 2 diabetes. Conclusions: We showed that the top characteristic associated with not developing Type 2 diabetes, despite being at very high risk, was a healthy diet, characterized by limiting Western dietary habits, but with a high intake of antioxidant-rich foods. This underscores the importance of diet in the prevention of Type 2 diabetes in people at high risk.