My question is why do i feel hungrier after i finish eating, or alternatively i have also experienced excessive hunger only 30 mins after eating ?

Check your sugar: could be related to your sugar iyour sugar fall instead of rising after eating then your body will be hungry to overcome the falling sugar. some people might end up producing too much insulin after eating that will cause the fall of your blood sugar. that is one of the explanation,ther is a lot of theory and centers in the body and the brain that are responsible for hunger and satiety. see doctor.

Prediabetes/Diabetes: or impaired glucose metabolism commonly causes a person to feel hunger even when they should not. Hunger is a powerful motivator and very difficult to overcome, therefore this often causes people to gain weight. There are medications available to specifically treat this problem. Consider a glucose tolerance test, especially if diabetes runs in your family.