Try adding flax oil and cottage cheese, neither are sugar based and follow the budwig protocol, and most importantly have calories and fats. Try chia as well. They make the shake a little thicker as well makes it easier to slide down. For a bit of sweetness add agave, or stevia they are natural and have minimal to no glycemic impact. (unless you dump in a bucket of agave)

Plus if you buy the sugar is poison theory - these are natural and good for you and sweeten.