When you have decided which protein bar you want, it is important to get a full review of the product from its ingredient list, to its processing and storage methods, and to the nutritional benefits that the product has to offer. There are many reasons for this. First, some products come with all of these details and are a must-have. Second, some are "all natural" and are not as advertised. Third, it is important to remember that the nutritional value of protein bars can change with time and with different manufacturing techniques. The following list contains a few protein bars that have changed in the past several years. A. Protein bars with high glycemic index The most recent protein bars to have undergone a major change in flavor and processing were the Barre Racer, Barre Racer Plus, Barre Racer Lite and the Banana Flavor Bar. These products are made with natural flavorings, but the products have gone through a few major changes in flavor since the introduction of the flavors. B. Protein bars that have low glycemic index The protein bars in this category have the highest glycemic index. This is a measure of the amount of calories per gram, based on a measurement of carbohydrate and protein content.