It's true. Carl is gated in the kitchen and we use training pads so that he can go potty while we're gone for a few hours, or during the night. He's very good about going on his pad. (At least when he's gated in the kitchen. Let him out in the rest of the house and it's too much freedom for a 3 month old- he'll pee all over!)
But he definitely eats his poop the second it hits the pad. If I could sit with him 24/7 and pick up his poop the second he went, the problem would be solved.
Here's my dilemma: I used to lock Carl in his crate at night. He would wake up every morning at 5 am to poop, so I would let him out to poop, pick it up, and leave his cage door open.
But lately I've been just leaving his cage door open at night. This way he can get food and water and go potty if he has to during the night. He still sleeps in his crate though, through the night.
But then he'll wake up to poop, and he'll eat it. The only evidence is a little smudge on the pad where he went.

It's not very practical to wake up at 4-5 am every morning so I can pick up his poop, ya know? Like this morning we actually got to sleep in (woo-hoo!) but of course he had already eaten his poop by the time we got up...
I've read that I can add meat tenderizers to his food, and I also read on various websites and forums that adding a little bit of pineapple/pineapple juice to his food would make his poop unappealing to him. Opinions? I've also heard that the deters they sell at pet stores that I can add to his food don't work...
I read that since he's gated into a section of the kitchen, he may be eating his poop to clean up his little space. When I catch him pooping I'll give him a treat and praise him as soon as he goes, and then whisk the poop away. But I don't usually catch him in the act, I normally just see the smudge on the training pad...ew...