Adjusting food during a growth spurt?

[rad10]

So I have a 14wk old pup, and I think he's going through a growth spurt. Periodically he'll yip and bite at his legs like they're hurting (growing pains?). My dilemma is that he's hungry ALL the time. The last few days he doesn't want to leave his kennel because that's where he gets fed, or he'll run out to the food bag and then back to his kennel wagging his tail and whining. After he eats he sits there whining and howling and licking the bowl. And the last three nights he's started throwing up bile at about 6am, which I suspect is due to an empty stomach.
He's being fed Nutrisource LBP. He's 34lb right now so the recommended amount is 3 3/4 - 4 1/2 cups. He's already getting 4 1/2 and has been for a while. His poop is solid, no diarrhea, he was last dewormed at 11 weeks, and he has a good waist both from the side and from the top (well... before meals at any rate). He's got a pretty short coat and I can see several ribs. Right now he gets fed at 7am, 1-1:30pm, and 7:30pm. Water goes up at 9, and his last trip outside is 11.

Do you think he needs an increase in food to get him through the growth spurt? If so...how much is reasonable to increase? I was thinking of maybe giving him an extra half cup or so at 9 right before I pick his water up... I could do it later but we just started making it through the night without bathroom trips and I don't want to give him food without water...But, of course, I will give him more water and sacrifice the sleep if he needs it. Is that reasonable? Should I do more? Later? Less?
Any advice would be appreciated

[wolfy dog]

Seems like an OK food except for the corn gluten meal and the chicken flavor (???).
What you describe sounds like a hungry pup. Pet him with a flat hand over his rib cage. If it is too bony or you see the comb on his spine he needs more food. Puppies should be trim but not too thin. Since he is biting his legs I would take him to the vet to check for Pano, common in young males and you can also ask about his weight. Don't let yourself be talked into the crummy diets that vets sometimes prescribe like Science Diet or Purina. (they sponsor vet programs). Forget what the package says; every dog is different in metabolism and activities.