His kind of weight gain you don't want LOL I've gotten that rotten system set up in me from time to time from the combo of candida die-off and being hypothyroid. I've jumped on the mini-trampoline, drunk salted water, loaded up vit C, moved my body to keep the trash moving out. It can feel like toxic stew inside, and disturbs my sleep when the lymph settles in my head and I can't breathe at night. I only know that the only way through it is to keep moving forward.
Yep, not enough vit C to help detoxification, not enough selenium to help the thyroid, not enough magnesium as a first line of defense against the a-fib, and not enough water and salt to dilute and move the toxic junk out of his system. He could have used gentle exercise as well, to help keep the lymph moving before it turns into sludge loaded with debris.