Group-based and online lifestyle counselling can support middle-aged and older men in making health-promoting dietary changes. These dietary changes, in turn, reduce the risk of type 2 diabetes, especially among men with a high genetic risk, a study conducted at the University of Eastern Finland shows.
The T2D-GENE study investigated the effects of group-based and online lifestyle counselling on dietary changes among men living in the eastern part of Finland, and how these changes influenced their risk of type 2 diabetes. The study also examined whether a high genetic predisposition to type 2 diabetes has an impact on the benefits gained from dietary changes.
Men in the intervention group received lifestyle counselling over a three-year period. The study found that lifestyle counselling delivered in group sessions and through a web portal helped participants adopt healthier dietary habits.
Health-promoting dietary choices were associated with a lower risk of type 2 diabetes, particularly among individuals carrying a high number of diabetes-associated risk genes. Moreover, participants carrying the genetic variant TCF7L2, which is known to increase the risk of type 2 diabetes, benefitted most from a fibre intake that meets the nutrition recommendations.
Participants in the intervention group successfully increased their intake of fibre, whole grain products, berries, vegetables, fish and plant-based oils. At the same time, reported consumption of sausages, high-fat cheeses, low-fibre grain products, sweets and butter decreased. By the end of the study, those receiving lifestyle counselling were, in general, consuming more health-promoting foods than those in the control group.
Numerous previous studies have shown that type 2 diabetes can be prevented, or at least delayed, through health-promoting lifestyle habits.
“We need to find resource-efficient ways within health care to support these lifestyle changes. Group-based and online counselling is more resource-efficient than individual counselling,” Doctoral Researcher Ulla Tolonen of the University of Eastern Finland notes and adds:
“Our new findings show that group-based and online counselling is sufficient to support lifestyle changes among individuals with a high genetic risk of type 2 diabetes.”
Participants’ consumption of individual foods was assessed using a food frequency questionnaire, while fibre intake was evaluated both through food records and by measuring plasma alkylresorcinol, which is a biomarker of whole grain intake. The incidence of type 2 diabetes and blood glucose levels were measured by an oral glucose tolerance test. Genetic risk was assessed either by a risk score calculated on the basis of 76 risk genes, or by the genotype TCF7L2, a known risk gene for type 2 diabetes. All participants had impaired fasting blood glucose at baseline.
The findings were published in European Journal of Nutrition, and in Clinical Nutrition.
Research articles:
Tolonen, U., Lankinen, M., Laakso, M, Schwab U. Changes in food choices and dietary patterns during the lifestyle intervention and their association with type 2 diabetes risk in participants with high or low genetic risk for type 2 diabetes. Eur J Nutr 64, 274 (2025). https://doi.org/10.1007/s00394-025-03791-x
Tolonen, U., Lankinen, M., Laakso, M, Schwab U. Association of dietary fibre with type 2 diabetes risk is modified by transcription factor 7 like 2 genotype in men with impaired fasting glucose: The T2D-GENE study. Clinical Nutrition, Volume 53, 262 – 269 (2025). https://doi.org/10.1016/j.clnu.2025.09.002