Being hungry after you eat a lot could mean you just have a big appetite and crave food and your stomach just is not satisfied with the amount of food you're eating or you could have another health condition.
If you are still constantly hungry after eating you could be getting diabetes or you may also have Leptin Resistance.
My sister was always hungry after eating and she got tested and was on the borderline of being diabetic so you should see a doctor about it and get tested.
Diabetes can be deadly if not treated in time so always get tested just to be safe.
Feeling hungry constantly even after eating is not normal and you should see a doctor about it.
You could have what's known as a Leptin Resistance.
Leptin is a hormone that is produced by your body fat that controls whether or not your stomach feels full after eating.
You may also have Hyperthyroidism which is a condition that is characterized by an overactive thyroid which can also cause you to have a constant hungry feeling.
So you should certainly get checked out by a doctor especially if you're always feeling hungry even after eating.