With most diets it always depends on your own body and what works for you. Personally, I avoided soy products, too many carbs and made sure I was eating enough protein. It sounds like you are having issues with getting full easily. I ate about 6 small meals a day, always including a protein in those meals.

I searched PLD support during my journey and found a website that publishes stories about those living with PLD and also has a tab at the top with diet suggestions specific to PLD. I can't post the URL but if you search polycystic liver disease it should show up.