It has 12 grams of sugar and 14 grams of protein. 10. Slim-N-Trim Vanilla The last low sugar drink on this list of smoothies from Smoothie King is the Slim-N-Trim in vanilla. This drink option only has 16 grams of sugar and is the perfect thing to get you through the day. It’s made with bananas, a protein blend, fiber blend enhancer and stevia.. "/>