It's kind of like taking a dog of a breed bred for smushed noses and experimenting with getting it to survive running a long time in hot weather. Because you feel bad that most of that breed aren't alliwed to do that.
Or taking a cat of that breed that has no hair and experimenting with...
I envisioned meaties being something like Prader-Willi sydrome. A member of my close famy has something similar although that has not been diagnosed and it probably isn't exactly that. He has been diagnosed with something similar. He has enough will power to not eat all the time but he is never...
If Smudge and Doodle are this desperate for food... have you considered that they might rather have a shorter life if it meant being comfortable. And maybe happier (between the food and the going in and out of their flock.)