ABSTRACT
The glycemic index (GI) is an important indicator in determining a healthy diet among carbohydrate foods. Diabetes and age-related macular degeneration (AMD), which can cause blindness, have been attributed to the consumption of diets with high GI. Foods classified as high GI foods contain carbohydrates that can be easily broken down, releasing glucose quickly into the bloodstream while low GI foods release glucose slowly. White rice, products from refined wheat flour (white bread and some breakfast cereals), tend to have high GI while some nuts and unprocessed grains have low GI. Root and tuber crops, on the other hand, have been touted to have low GI, in addition to the provision of relatively cheaper calories. As a result, wheat flour is being substituted with root and tuber flours for baked food products such as bread and other wheat-based products in Africa, the home of root and tubers. This chapter discusses the glycemic index of four root and tuber crops grown in Sub-Saharan Africa and also identifies gaps and suggests areas for further research studies; their reported GI, and impacts as substitute flours for GI. The nutritional benefits of these crops are also highlighted. Low GI foods are useful in treating hyperglycemia, and in the management of diabetes. Despite their low GI, root and tuber crops are known to be useful nutraceutical plants.
