Like quite a few out there, I'm sure, I've experimented with various adjustments to diet/health for years.
For me, the two main food-related changes I find to be of the most benefit to how I feel, not necessarily the way I look, is to keep my carbohydrate intake fairly low (not keto levels as yet but pretty close).
And the other is to food combine, so for example, not eating protein with grains and starches/fruits(or fat with a carb/sugar). Better for a reduction in glycation as well, in theory.
I don't see me going back to upper-moderate levels or above for carbs in the future, though I may bump it up a little. Time will tell.