Just because we traditionally eat certain items for breakfast for breakfast, that doesn't mean you can't break with tradition occasionally and eat whatever's available --- leftovers, meat, and the like. Heck, some British eat kippers -- smoked fish -- for breakfast.

While it's never a good idea to skip any meal, it's especially bad to miss breakfast. Most people have low blood sugar early in the morning, and blood sugar is the fuel that makes the body run. Even if you're in a hurry, at least have a slice of toast or a bagel.

Some people find it difficult to eat much for breakfast, but even if that's the case with you, you need to force yourself to eat a decent amount. After all, you're "breaking the fast" you've been on since supper the previous night before, and so your energy is probably very low.