DS is on Orkambi and during the week he usually takes it around 7:15 with breakfast -- lately he's been eating a gogurt, uncrustable (PB & jelly sandwich) and drinks carnation instant breakfast or whole milk. Then he take his 2nd one around 6:30 with supper. If he sleeps in he usually has it with breakfast/lunch and then around 9:30-10 he has a snack or at the very least takes it with a glass of whole milk.
His snacks include buttered popcorn, peanuts, almonds, trail mix, aged cheddar, jerky, kashi nutbutter bars, Cheetos, handful of tortilla chips and whole milk. I have gotten him smaller whole milk yogurts at trader joes, ice cream -- something that is high in fat and calories, but slips thru the cracks if he's not all that hungry. Not sure if you're a meat eater..., but last summer my father in law purchased a huge bag of sliced pepperoni -- DS had been eating grilled cheese with pepperoni and I had no idea what to do with such a large bag. A friend suggested baking them into chips. She spreads them on a baking pan and bakes them at 400 F for about 6-7 minutes until they get crispy.