Treatment is worthless if he WANTS to be fat, its ridiculous, as I said if he really wants to lose weight and they offer to put him up in a facility that controls all of his food and he will have no choice to have extra, he either wants to be thin, signs on the dotted line and loses most of his weight very very quickly. Or he refuses the treatment and signs a different piece of paper that says he's refusing treatment and can do as he pleases and his doctors are no longer responsible for him.
He's 70 stone for god's sake, he literally has no chance of living to 90, he'll be lucky to live another 10 years, even if he loses 60 stone, losing 60 stone isn't going to make him instantly healthy. He'll have a heavily taxed, heavily worked, incredibly unhealthy heart, lungs, kidneys, liver, spleen, etc, etc, etc. If he lost 60 stone in the next 10 years, I still wouldn't give him more than a 1/100 chance of lasting 10 years after that.
He's probably very close to serious other health issues now, if your average fat guy starts getting into big risk ages for heart attacks at 50-60, at 48 and 70stone, this guy is a heart attack waiting to happen. After a heart attack, exercise and strengthening your heart is a huge part of preventing another one, at the moment he has no chance of that.
He needs radical change to the way he lives, not a few staples in his stomach, if he truly wants to get healthier and lose his weight, why would he not sign a consent form to be taken to a "fat camp" type place to lose the weight.