Overweight and obesity associated with excess energy intake, Western dietary habits, and low physical activity are the major reasons for the rise in the prevalence of T2D. As a result of this adverse development, global and regional diabetes related health expenditure is expected to rise significantly.

Observational evidence has suggested that whole grain food (WGFs) is beneficial to T2D. This finding has also been supported by a study that has emphasized the consumption of WGFs as a way of increasing fiber in the diet.

In addition, fiber-rich food may offer important beneficial effects, including glucose and metabolism control as well as in many other conditions. Thus, whole grain food may have significant health and economic consequences regarding the prevention of T2D in the population.

WGFs have been widely recognized as healthy foods due to their high fiber content, antioxidants, and phytochemicals. Human trials have shown the potential of a diet enriched with WGFs in reducing fat mass, increasing metabolic rate, promoting negative energy balance, increasing insulin sensitivity, improving lipid profile, and reducing systemic inflammation. Epidemiological studies have shown an inversed association between the consumption of WGFs and the risk of developing several major chronic diseases, besides T2D: cardiovascular disease, obesity, and some types of cancer.

Most of these observational studies so far, have characterized the intake of WGFs as the sum of WGFs ingredients from all grain containing foods, which might contain various amounts of WGFs and refined grains. Despite a similar proportion of bran and germ (about 13% and 2%, respectively), individual WGFs foods usually contain various amounts of dietary fiber, antioxidants, magnesium, and phytochemicals, which might result in differential effects of different types of WGFs on cardiometabolic health.

Higher consumption of total WGFs and several commonly eaten WGFs foods, including breakfast cereal, oatmeal, dark bread, brown rice, added bran and wheat germ, was significantly associated with a lower risk of this conditions.

Eating WGFs may also decrease the risk of overall mortality by up to 9%, according to a study from the Harvard School of Public Health that involved more than 118,000 people. Risk of death from cardiovascular disease dropped even further, by up to 15%. These researchers found for each serving of whole grains, the overall death risk dropped by 5% and by 9% for deaths related to cardiovascular disease.

In another finding, bran intake was linked with up to 6% overall lower death risk and up to 20% lower risk of WGFs death related to cardiovascular disease. Switching one serving of refined grains per day with one serving of WGF was linked with an 8% lower mortality risk related to cardiovascular disease. Switching one serving of red meat per day with one serving of whole grains was linked with a 20% lowered mortality risk related to cardiovascular disease.