Some people spend the last ten or twenty years of their life in and out of the hospital, and some just fall over from an aneurysm after otherwise perfect health. Obesity (really type II diabetes, which morbid obesity pretty much guarantees) really pushes people into the first camp.
But sure, a smart watch won't keep cancer from metastasizing, and staying out of the obesity BMI band only decreases lifetime cancer risk, doesn't eliminate it by any means.
What this thread needs is an actuary...
