Extra Fast Keto Boost blood glucose blood sugar levels induced by specific foods. It was created to help relate the impact of food or more specifically carbohydrates on blood sugar levels. On the glycemic index, foods are given a rating from to . Foods with a high glycemic index increase blood sugar levels rapidly. Foods with a low glycemic index increase blood sugar levels slowly. Extra Fast Keto Boost REVIEWS 2019 | Weight Loss Discovery! Please note, the glycemic index will not apply to all people evenly, all the time, as different people will have different reactions to the food they eat. In addition to this, the impact of a specific foods on blood sugar levels, may be greatly affected by the amount of fat and protein eaten with the carbohydrates, how refined the carbohydrate is and how the carbohydrate is prepared cooked, boiled or fried, for e.