Why would my cat be eating more than usual?

My cat (male, about 10 years old) recently seems to be hungry a lot more. whenever i pass him he ends up rubbing against my leg, what could be the reason for this? he seems to be in perfect health and hes pretty average sized. we recently switched him from felix cans to felix pouches which he seems to prefer, could he be wanting food for pleasure instead of hunger, and if so how many pouches should cats be on per day?
Answer
Maybe he has worms? have you wormed him lately?