I've learned that DIET is paramount.

I was living what most people would have considered a very health lifestyle a year ago. So basically:

I had medium energy with this lifestyle.

But starting the carnivore diet (i.e. only animal products, which is of course also almost zero carb) has been a complete game changer. Within 3 weeks I had so much more energy. Then as my body has become more accustomed to getting energy mostly from fat, my energy levels have gotten even better.

I'm rarely tired now, and am full of ideas, projects, and plans. It's not something I expected to happen with a dietary change, but that's what happened.