Overview

• The T2D-GENE randomized lifestyle intervention enrolled middle-aged and older men with impaired fasting glucose and delivered counseling through group sessions and a web portal over three years.
• Participants increased consumption of fiber, whole grains, berries, vegetables, fish and plant-based oils while cutting processed meats, high-fat cheeses, low-fiber grains, sweets and butter.
• Healthier food choices were linked to a lower incidence of type 2 diabetes, with larger relative risk reductions among men with high polygenic susceptibility.
• Genetic risk stratification used a 76-variant score and the TCF7L2 genotype, and meeting fiber targets was especially protective for TCF7L2 carriers.
• Diet and outcomes were assessed via questionnaires, food records, plasma alkylresorcinol biomarkers and oral glucose tolerance tests, and results were published in European Journal of Nutrition and Clinical Nutrition in September 2025.