True story.  My stepdad (he is my dad, just not biologically speaking) and his brother have both had to have quintuple bypasses.  Both are fit and thin.  My dad works outdoors all day every day doing lawn and landscape (snow removal in winter).  Uncle spends his time working on his farm.  Shitty genetics happen that predispose even healthy folks to cardiovascular diseases.  Being fat, however, predisposes you to cardiovascular diseases even when you're not genetically predisposed.