Although the oral glucose tolerance test (OGTT) has been historically the clinical standard for diagnosing and categorizing changes in glucose metabolism, glycemic phenotypes (e.g. impaired fasting glucose versus impaired glucose tolerance), and diabetes, a mixed meal tolerance test (MMTT) is more akin to daily intake as foods are often solid and there is a macronutrient mix of carbohydrates, fats and protein which each uniquely stimulate insulin secretion [4, 6–9]. This evidence concerns the gene INS and diabetes mellitus.