Previous epidemiologic studies associated a high consumption of red and processed meat with an increased risk of type 2 diabetes, whereas high dairy intake was associated with a reduced risk. Researchers at the University of South Australia compared in a new randomized cross-over study the impact of a diet, high in red meat and minimal dairy consumption, with a high intake of low-fat dairy (including milk, yogurt or custard) and no red meat.
47 overweight or obese men and women participated and were divided into two groups, according to a normal or impaired glucose tolerance. During 4 weeks they followed a 3 weight-stable dietary interventions. Glucose, insulin and C-peptide were measured by oral- glucose-tolerance test at the end of each diet.
Reduced insulin sensitivity in obese women
The results showed an increased fasting insulin level after the dairy diet, compared to the red meat diet, and as the fasting glucose did not change, the insulin sensitivity decreased. A significant correlation was observed between sex and diet: the insulin sensitivity in women was 14,7% lower after the dairy diet compared to the red meat consumption, this correlation was not found for men. Neither did the C-peptide level change according to the different diets.