Type 2 diabetes has been a 61% increase in incidence between 1990 and 2001 in the USA. There are 1.5 million new cases per year. Poorly-controlled diabetes that is characterized with increased glycated hemoglobin, HbA1c8%, is increasing world wide, and gestational diabetes mellitus (GDM) affects a substantial number of pregnancies, which complicates 7% of all pregnancies. Substantial evidence from studies support the dietary fiber and types of carbohydrate (glycemic index and load) impact on postprandial glucose and insulin responses. High carbohydrate intake recommended in diabetes, resulting in suboptimal glycemic control and lipoprotein profile, gradually increasing insulin and/or oral hypoglycemic medication requirement and eventually weight gain. Therefore, we investigated the role of low glycemic index-glycemic load diet with and without extra fiber (wheat bran) on blood glucose profile of insulin resistance, diabetes and GDM subjects. The diets included lower amount of carbohydrate and higher fat content than traditionally introduced diets as an alternative approach to reduce glycemic response to carbohydrate and also reducing HbA1c concentration of poor-controlled diabetes