I am mid 50s and have watched the rise in obesity in the US. I think if you say metabolic disease is the biggest HEALTH problem facing individuals, I agree. Obesity in particular complicates every aspect of care for people. Not the biggest problem overall, that I would say is the degradation of environment and resulting climate impacts.
Personally, I just try to stay in shape, stay active, not get fat, eat real food mostly and don't worry about cholesterol, do take BP meds to keep it below 117 SBP.