Glycemic index (GI) is the ranking of food based on the post prandial blood glucose after consuming a carbohydrate rich diet whereas glycemic load (GL) or glycemic stack of sustenance is a number that evaluates how much the food would raise a person’s blood glucose level after consumption. Very little is known about the effects of carbohydrates, specifically any association between glycemic index/glycemic load and diseases. The Carbohydrates which are slowly digested, absorbed and metabolized in the human body are classified as low GI foods (55 or less) leading to slow rise in the blood glucose and therefore insulin whereas carbohydrates with a high GI (>70) value leads to hyperglycemia. The constructive and destructive health effects of dietary carbohydrates are of concern to both scholars as well as shoppers. Many supportive evidences have been discussed which highlights the significant link between GI/GL and risk for diabetes mellitus, cardiovascular disease, retinal disorders and the recent being acute macular degeneration. The intent of this review is to critically analyze the scientific evidence on the role of GI in human body and how is it interconnected to several metabolic diseases such as CVD’s, cancer, diabetes mellitus, retinal disorders. GI may serve as a practical criterion to assist people in order to opt healthy choices.