Breakfas buffets almost always have piles of bacon and scrambled eggs That should be your easiest meal of the day.
For the rest of them - be explicit in your ordering, if it isn't on your plate you won't eat it. Make sure they don't bring you a potatoe with your steak (ask for some high water content veggie instead). Make sure they "hold the croutons" when getting your grilled chicen caesar salad.
With a little planning you will do fine!