Being hungry even after eating is sometimes normal if it doesn't happen all the time.
However if it's happening all the time and you still feel hungry after eating then you could have resistance to Leptin.
Leptin is a hormone produced by body fat which controls whether you're full or not after eating.
The body is supposed to secrete Leptin when your stomach is full and you've eaten enough and then sends a signal to your brain telling your brain that your stomach is full.
When you have a resistance to Leptin then your brain doesn't get told that your stomach is full and as a result you feel hungry even after eating.