There is a strange connection between what you eat and how full you feel. You would imagine that the size of your portions would have something to do with it. Eat more and feel full as it were. Quantity undoubtedly matters. If you ate a lot, you would feel full right after. However, depending on what you ate, you could quickly feel ravenous in an hour.I experienced this first hand a few days ago. At a gathering I was invited to, I ate white bread after years. It was well toasted and extremely tasteful. I ended up eating many slices for the taste alone and felt stuffed. Within thirty minutes I was starving again.
What you eat affects not just your sense of hunger but also the activity in your brain. Researchers attempted to study this phenomenon by examining the brain after eating walnuts. Walnuts (by the way an excellent evening snack) make you feel full in small quantities. Two walnuts are fifty calories, so it is not surprising. Also, they come loaded with minerals and Omega 3 oils which take time to break down in your body. It is this that makes a difference between walnuts and white toast. In a group of people who included walnuts in their diet, their brains showed increased activity in a part of the brain called the right insula. This increased activity was the brain signaling you that you were full and did not need to eat more.
Science has a beautiful way of quantifying evidence. Anectodally, you can experience the same thing. Switch from fast burning simple food to more complex food that takes longer to break down, which surprise of surprise, includes foods that include good fat, and you will find yourself feeling full. Portion sizes will fall, and you might even stop raiding the refrigerator.