Breakfast doesn't have to consist of a large meal, either. An ouce of cheese or a few slices of deli roast beef or turkey spread with cream cheese and rolled up or a hard boiled egg would do. As long as you're eating something and not skipping eating altogether.
Metabolisms are a lot like a furnace. As long as the furnace is getting a steady supply of fuel, it continues to burn hot and steady. If you stop giving it fuel or give it fuel inconsistently, it burns cooler and slower. Eating regularly keeps that metabolism furnace burning high and steady.