All protein bars share one valuable characteristic - convenience. Bars are a quick, easy substitute for a light meal or snack. Convenience and compactness are especially important for athletes who train or compete for several hours and need to eat. Some bars provide almost all of their calories from carbohydrates, which is useful for endurance athletes who want to add carbs to their diet to replenish depleted energy stores. Other bars are more balanced in nutrient make-up and tend to have much higher levels of protein and fat. When looking for a low carb bar be sure to check the label for " Net Carbs". Try Pure Protein Bars, Muscle Sandwich and Met-Rx Big 100 Colossal Bars.