Low in fat, low in salt, low in sugar, bland (not spicy because it makes me itchy), using bran cereal and prunes for fibre.
I eat cheese, eggs, milk, yogurt. I eat meat, and more is better (reduces itchiness), and the quality of the meat counts. If I buy sandwich meat, it's mainly chicken breast. All the others are pretty salty or fatty. Also, for dinner meats, chicken is better than ground beef. (The food I get the least energy from is spaghetti with ground beef.) I eat steak occasionally. Fish is good once a week. Skinless chicken breasts are better than chicken legs or thighs because they are lower in fat.
I eat oatmeal cereal every night.
My gastroenterologist said to drink two cups of coffee per day because there is some evidence it slows the progress of the PSC. He only told me that this year (in this the 15th year of visiting him and having PSC). I'm trying that. Also he suggested taking probiotics and vitamins. I haven't tried these yet.
Sugar can make me incredibly tired if it's in baked products, so I try to avoid cookies, cakes, pastries, and the like. However, if I add it to homemade strawberry sauce, oatmeal, or coffee, it seems to be okay.
I eat avocados daily as a sandwich spread. I eat a salad every day and one cooked vegetable.
Very little processed food. Some fresh fruits (oranges, pears, apples, bananas mainly.)
Hope this helps you or somebody reading this!