Yes, worms will make him hungry. The worms are taking out the nutrition from the food...and leaving him with little.
What kind of food are you feeding? I would also suggest once puppy is fed, to put the bowl away...so there is no hanging around the bowl.
Most Rottweilers are always starving....I've never had one that thought they've had enough.
You want slow, steady growth and the way to do that is to measure out their food.
Gina