Variety is also key to a healthy diet. As much variety as possible.
Pumpernickel rye bread is tasty and filling. Good fiber. Low sugar for a bread. Goes good with peanut butter. Doesn’t get soggy before lunch, etc. It’s got 0.2g sugar per slice and a low glycemic index so it’s good for diabetics.
It’s not popular here in the states, though. It’s hard to find. Personally, I can’t get enough of the stuff ever since I tried it. I always snatch a loaf when I run across it.