It seems that I always get hungry within two and a half hours after eating, even if I am initially full right after finishing a meal. I have been trying to just drink water whenever this happens, which helps, but doesn't completely take away the hunger. What could be causing this? Is there anything else I can do to stop it? I am trying to lose weight and this is really hindering my weight loss efforts.

Fiber and protein keep you fuller longer.
Carbohydrates take less time to digest and therefore they make you hungrier.
But it's my own fault, I'm trying to massively gain weight for bodybuilding and boosted my metabolism sky high.
if you're losing weight, shitty deal.. you just have to ignore it and hang on there! Do a lot of cardio too, helps burning fats and if you do enough you feel like vomiting afterwards -will keep you away from food for a while.