High-quality, low-carb protein helps you feel fuller longer.Protein Bars can help you lose weight with 21 satisfying grams of protein. Enjoy sweet cinnamon bun taste sweetened with rebiana, a zero-calorie, SteviaTM-based, all-natural sweetener. What is the protein source used in the bars? Protein is supplied by quality protein sources whey protein isolate, soy protein isolate, and whey protein hydrolysate.