ROFL....oh my god, I shouldn't be...but you just brought back sooooooo many memories.
Short background: I'm the littlest in my family, & I'm over 6 feet tall. My son at six is 4 and a half feet tall. He ate alllll the time (not for the same reasons as yours, obviously), but the results were the same. Oh my goodness. Ugh...Having to use babywipes up to his ribs or his neck was NOT an infrequent occurrence. Especially on days where my mum watched him for me. My god...don't some people realize that you don't give a baby x,y,z??? :P So glad those days are over.
Some of the things we did to combat this probably won't work for you. I was in school when my son was an infant, so the only time I could study/write papers was at night & naptime...so I was up until 1 or 2am, and then back up @ 6 or 7. Maybe you can get by on that little sleep. I'm only able to do it under duress. Also, he's our only, so it's super easy to tailor a schedule to one child.
What we did that finally worked: (for us)
* * * - Change his diaper in the middle of the night. Sometimes twice. I'd change him around midnight, and then check and see if he was wet again right before I went to bed. By the time he was about a year I could wake him up enough to ("Do you need to go potty, love? need go potty?") & he'd pee one more time BEFORE I put a new one on him. The combo of a soaked to explodium proportions diaper and then a poop in the morning IN that diaper was a combo I was willing to risk "waking the baby" to avoid.
- Switched to PullUps Overnights right around a year. We had him in diapers in the daytime...but the pullups overnights work as well as a diaper, & are MUCH MUCH stretchier. I honestly don't remember if the overnights have velcro or if I had to rip the seams. By 18mo-2years he was in pullups full time...but we weren't potty training him yet. They just FIT. (On a side note: he started pooping in the daytime right about the same time we switched him. Could be coincidence, could be that not having the diaper so tight around his abdomen allowed it to happen easier.) We found namebrand to be worth it. Sigh.
- INCREASED his dairy, specifically milk. He had a straw cup with him at all times. Obviously a lot more wet diapers...but it would help keep his food intake about where it should be, because the milk helped keep him feeling full (and gave him the quick sugar, fat, & protein that he needed to keep his temper. He was also SUPER active & come to find hypoglycemia runs rampant on daddy's side of the family. So perhaps H20 would work better for one needing to shed pounds, but we never tried it.)...anyhow the more hydrated he was the more frequently he WOULD poop...so in smaller amounts...and not just the nightly blowout.
- Increased the number of meals he ate in a day. (Um...obviously not the quantity). Gorging, like he would do at my mums with 3 meals, meant guaranteed disaster in the diaper department. A nibble of something every hour or two worked wonders. I'm wondering if it might help your shell shocked little one, too?
Anyhow, like I said, that's what we found worked for us. I DO have to tell you, I was tempted on more then one occasion in the beginning (around a year old) to get rid of the sheet entirely, or short sheet the bed so that his face wouldn't stick to the plastic, but so I could spray off the waterproof mattress without having to do laundry. I never actually broke down and did either, because we found some things that worked for us...but I suppose those are two more options.
Best
R.