There may be heterogeneity in the response to a lifestyle intervention to prevent type 2 diabetes. This study investigated whether participants of Tübingen Lifestyle Intervention Program (TULIP) type 2 diabetes risk clusters 3 and 5, who have a very high risk of diabetes, benefit from long-term weight loss following a 2-year lifestyle intervention. Diabetes risk cluster 5 participants had an impaired response regarding improvement of glycemia and insulin secretion and a high risk of developing type 2 diabetes, despite a long-term (9-year) mean weight loss of 8%. Alternative or intensified interventions should be considered for people in Tübingen type 2 diabetes risk cluster 5.