Exercise

Sleep

Nutrition

Everything else is secondary to those 3.

Exercise should be a mix of cardio and weightlifting.

Sleep should be ~7-9 hours of sleep daily

Nutrition should be plant based, leaning away from processed foods and more towards whole foods.

Avoid alcohol and minimize sugars.

This is the foundation to solid health.

There is also a mental element: one should be doing mentally challenging things to minimize brain atrophy. Keep your brain challenged