A combination of exploded medical subject headings (MeSH) and free text searching were used, including ‘Type 2 diabetes’, ‘NIDDM’, ‘high carbohydrate’, ‘higher carbohydrate’, ‘carbohydrate rich’, ‘high glycemic index’, ‘low glycemic index’, ‘glycemic load’, ‘hemoglobin A, glycosylated’, ‘fasting plasma glucose’, ‘postprandial glucose’, ‘insulin sensitivity’, ‘insulin resistance’, ‘cholesterol’, ‘triglyceride’, ‘HDL-cholesterol’, ‘LDL-cholesterol’, ‘body weight’ and ‘obesity’. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.