I went thru the same confusion after my EPI was discovered. Dr said nothing re: how, what or when I should eat (after having lost 35 lbs in 15-18 months much of which I must assume was muscle.)
I began on no diet since I was not given a diet, but started by eating normally but more often and drinking 2-3 bottles Ensure daily and gained about 3-4 lbs in first 3 months so asked Dr if I could cut back from 4 to 3 12K Creon to 'test' myself to which he said yes. THat was around Oct 2022 and by Xmas I had lost the 3-3.5 pounds I had gained. Dr never had given advice on what to eat. His PA told me to take at least the first 3 of the recommended 4 CReons with 'a meal' and then I could take the last (4th) Creon in the evening with a few tbsps of apple sauce and a piece of toast.
When this did nothing for me, I tried to find an 'EPI Diet' on internet and found the usual Mediterranean type diets, etc in which there were very few calories and ultra-complicated (IMO) meal prep. As my weight hovered around 138-140 I asked the Dr JUST WTH SHOULD I EAT to gain weight! Surprisingly, after about 9 months of floundering around and looking for a system or protocol of gaining weight, Dr replied "Eat everything! Pig Out! I just want to see you get calories so you can put some pounds on." I asked him about calories and he said (for the first time in a year!) that I should eat 2,000 calories a day.
I started buying pre-cooked meals @ Costco. All kinds according to the caloric content for certain amounts in ounces or grams so I could eat a 'main' dish at at least 300 calories then take something else like Ensure (220 ca) potatoes etc to reach the 500 target.
I am hardly ever hungry enuff to eat 2,000 calories in 4 meals as I feel that it takes me at least 3 or more hours to simply DIGEST the 500 calories I ate before it's time to eat again.
I eat a lot of pasta, roastbeef, pancakes, 1 cup Old Fashioned oatmeal every morning (300 calories) and 8 oz Ensure with it. I eat 1/2 an avocado with some 'meals' since I found avocado has fat and 1/2 avocado is about 140 cal. My cholestrol has always been low and I am thinking to have my GP check it every so often to make sure trying to 'fatten up' is not affecting that.

Since starting the Ensure again about 6 weeks ago and trying to get close to 2,000 cal a day I've gained about 4.6 pounds. For some reason, I personally think the Ensure has as much if not more to do with my slight weight gain.
I don't know if this helped or not, but I do know that it took me some months before I finally near-challenged the Dr to TELL ME THE NUANCES OF HOW AND WHAT I SHOULD EAT!
Long story short, he must have thought that NOT telling me to go on a certain diet would cause me to eat no differently on Creon than I would eat before the EPI was discovered.

As I get older, encounter COPD and emphys, A Fib, Stage 3A kidney, etc., I truly find that too many doctors treat every patient as a lesser organism and for this reason the doctors themselves have learned to pay little or no attention to a patient who thinks and remembers and asks questions in DETAIL.
In that fashion, it's actually the PATIENTS WHO SPOIL the doctors b/c the patients look to the doctors as being minor gods who have no faults and the DRs are not moved or forced to be more specific with each patient..

I have been to Drs who should not have been allowed around a patient and also to some doctors who spoke and stood or sat in such blissful calmness that you could sense their concern and sincerity coming thru their faces eyes and skin.

Then again - things are different today: In the late 70's / early 80's A noted Diagnostician from a well known midwest university hospital told a relative of mine in Chicago that hospitals were 'becoming corporations.' A GP has very little time with a patient save to refer him/her to another physician in the same hospital system; Doctors also are too busy to spend the time it takes to gain an instinct for the several problems individual patients bring to their offices. Etc..etc..

Just recently here in Michigan, Beaumont Hospital system joined with a system called Corell or some similar name. In the first week of their 'joint venture,' my wife and I both received a letter stating that much if not all of Beaumont's health records were "accidentally" compromised! I had to wonder if it was truly an 'accident' or not!!

And I still do.

Good luck and Blessed wishes to all...

((Pig Out - Take the Creon and see what Happens!!))