The number 1 cause of chronic disease, including heart disease, many cancers, Alzheimer's, dementia gout and (almost) anything you care to name, is poor metabolic health.
Let me explain:
Poor metabolic health is most commonly visible to the naked eye based on 2 factors:
-Excess body fat (being over fat, no matter the BMI)
-Low muscle mass (being under muscled, again, no matter the BMI)
The official term for poor metabolic health is insulin resistance.
My shortcut is this: the opposite of poor metabolic health = being lean and fit.