too much fat will make you have the orange explosions in the potty, and too many carbs will make your insides cry with gas pains and the resulting smells are noxious (combined with orange explosions, be careful.. jus' sayin').
With a DS, it's protein first. I could tolerate Bariwise cream of chicken protein soup, but not any bouillon broths. Not even store bought brands. Everyone is different, but the average amount of protein a DS'r absorbs is 60% of intake. To reach the amounts the body typically needs, 130-150g of protein should be the goal per day (unless otherwise indicated by doctor).
P.S. (edit) It took me about 6 weeks to reach that goal and I am still falling short of it. I had another doctor botch my DS in 2010. I had a revision with corrected limb length on April 18, 2022.