Wheat

Epidemiological studies suggest a relationship between whole grain intake and insulin sensitivity. In an effort to investigate this possible relationship a randomized controlled trial was conducted by a group of European scientists. One hundred and forty six individuals were recruited in two European cities (Kuopio, Finland and Naples, Italy) and randomized into two groups. One group consumed a diet based on refined grains and the second group was given a diet based on whole grains. After a 12-week period where good adherence was achieved, there was no significant difference in insulin sensitivity measures between the two groups. 
Clinical Nutrition. 2013. [Epub February 8, 2013] (Giacco et al.)