I don't know of a way to merge nutrition information about several foods.
You probably know this somewhat tedious and painstaking method:
You could write down the information yourself from each food in the quantity you use (for example, 2 fried eggs, 2 pieces of toast, two slices of fried bacon), add them up and then manually enter them in a custom food. 'My fried egg breakfast' could be the name.
Then each time you have that breakfast, you can choose that custom food.
It takes a little time but if you really eat the same things a lot, it probably makes life easier. You won't have the vitamins, minerals, etc., carried along with it - but that is always the case with custom foods.