<1g sugar per serving. 11g protein. 1 g net carbs per serving. Quest Peanut Butter Cups. Satisfy your sweet tooth with less than 1g of sugar, 11g of protein and 1g of net carbs per serving. Can you believe it? Take a bite and find out for yourself. Quest Nutrition is on a mission to make the foods you crave work for you not against you. 13g carbs – 4g Fiber – 8g Erythritol = 1g Net Carbs.