I mix it up all the time.
If I'm working, breakfast is usually a shake, day off breakfast is eggs, pancakes or oatmeal.
Midmorning I have a shake or bar.
Lunch is soup, puffs, pretzels, or lean & green.
Afternoon I like a shake or bar.
Dinner is usually lean & green, sometimes pancakes or eggs.
Evening I love brownies or hot cocoa, sometimes a bar.
But if some day I wake up and want a brownie for breakfast, I'm going to go for it!