The first question I would have asked was when they were wormed last, so thanks for putting that info in first up.
Puppies do have roly-poly tummies, but what you are describing osunds a bit more, hard to say.
Are they otherwise as active as usual? Do they appear restless? Do they seem to be in any pain or discomfort? If you were to push LIGHTLY on their distended abdoemens, do they appear to then show any discomfort?
Too much food too fast can be a killer Mollinator. Literally.
Aren't these the three puppies that you said in naother thread are somewhere possibly between 5-7 weeks? try giving them lots of much smaller meals for a while, see how that goes.