The reason for feeling hungry

I have breakfast at 8:30 this morning.  2 fried eggs and a cup coffee.   It is about 300 cals.   I should not be feeling hungry right now at only 11am.   But the problem is that I feel hunger. 

What is the reason for the hunger?    I couldn't tell.   The one thing I would do is follow my guidlines for eating.  Lunch is at 1pm.     I drink a huge cup of tea.  It didn't help much.   I'm not really thirsty.   

Will follow the exact time set for breakfast/lunch/dinner help with this problem of feeling hungry?  I certainly eat enough food nowadays.  Should I eat more vegetables?   I have enough protein in my diet.  And still have to cut down on the fat a bit.

So exactly what is the reason for the hunger.