Some Soy milk brands used to have different versions and some tasted better and were more of a desert flavor with more Calories but a tiny bit less protein per serving of the same size than the version with no sugar added

However my experience has been the no sugar added version makes me feel more full making it more difficult to get enough protein in the day despite the reduction of protein per serving

I have found soy, beef, chicken, cheese, yogurt & kefir to be easy to digest protein