Unless I misunderstand QALY, wouldn't n+5 years of misery not necessarily equal n years of actual quality life? assuming a base quality of 0 < k ≤ 1 with n years, and a calorie restricted life at quality 0 < k' < k with n+5, surely you'd end up at k * n QALYs for a normal life, and k' * (n + 5) for a calorie restricted one? Which might very well be lower given how large n is and how much smaller k' is than k.

Concretely: 85 years of misery is not 5 QALYs more than 80y of normal life.

Or am I missing your point, here?