Background/Aims: In contrast to some epidemiological evidence our previous research found that a 4-week diet high in dairy reduced insulin sensitivity compared to one high in red meat. Our aim was to investigate whether a dairy meal produced lower glucose compared with a carbohydrate-matched red meat meal.
Methods: 19 men and 24 women (age 50.8 ±16.0, BMI 30.0±3.5 kg/m2) completed the randomized crossover study. 22 participants had normal glucose tolerance; 21 had impaired fasting glucose and/or impaired glucose tolerance. One meal contained lean red meat, bread and orange juice and the other milk, yoghurt, cheese and bread. Meals were isoenergetic, equal in macronutrient profile and consumed one week apart. Glucose and insulin were measured before and 30, 60, 90, 120, 150 and 180 minutes after consuming the meal. Difference between meals was tested using repeated measures ANOVA and paired sample T-tests.
Results: The red meat meal resulted in a higher glucose response at T30 (p<0.001) however total glucose AUC was not different between meals (p=NS). Incremental AUC for glucose was significantly higher after the dairy meal (2.23±3.19mmol/L vs 0.88±3.73mmol/L, p=0.004). Total and incremental insulin AUC was not different between meals (iAUC 159.65mU/L for red meat, vs 167.49mU/L for dairy, p=NS).
Conclusions: Lean red meat and dairy meals produced a similar glycemic response. The higher glucose response 30 minutes after the red meat meal is likely attributable to differences in glycemic load between orange juice and milk/yoghurt. An insulinotropic effect of dairy was not observed.
Funding Source: University of South Australia