I'm big on real fruit & veggies, and a daily intake of each, separated by proteins and carbs.
I do take a multi-vitamin just to "ice the cake", so to speak.
Very rarely eat fast food, no soda-pops, and I watch my sugar & sodium intake.
I never eat dairy & meat together - very little dairy, actually - the no-dairy-with-meat is a practice that dates back to Biblical times.
I'm 70, and all my levels & vitals track like I'm much younger, including blood pressure & such. 5'10" and 165 lbs. BP 120/75.
Haven't had a cold or flu in decades, let alone all the other stuff people younger than me suffer.