To reduce weight I presume that you have make an assessment based on the feelings that the stomach is communicating to you.
The idea is simple. I will try this approach. If I sense my stomach is feeling a little full and I want to eat something besides regular meals. I will just eat tiny amounts of cereal. Nothing else. Just a little cereal with out nothing but water to drink afterwards.
The idea is to achieve the opposite of feeling full. That is to feel a little tension in the stomach. Here the guess is that its not energy only that the body needs fat for.
However if it does not feel good or right it simply does not work for you.