Oatmeal (like that new wonder-food that can do no wrong, chia seeds) absorbs a lot of water, and is loaded with fibre, both of which make it an excellent food to stave off those hunger pangs, while using very few calories to do so. The perfect way to start the day.
Specifically, the egg whites. 100 grams contain just 52 calories and those calories are packed with protein. My suggestion though, would be to hold on to the yellow of the egg, as well – it contains half of the egg’s protein! Eat it boiled, half-boiled, even scrambled (but without butter) and that’s just 80 calories! The minute you add oil or butter, the calorie count goes up dramatically.