Peter Attia followed Tim Ferriss's Slow Carb Diet, which involves consuming meat, vegetables, and starches, with a weekly cheat day, and found it effective for achieving leanness and supporting mental energy.

“I was and I still am a big fan of Tim ferriss's uh slow carbohydrate diet because I like to eat meat and vegetables and starches I'm an omnivore um and I found that it worked very quickly got me very lean I could exercise I could think I could sleep all you know a lot of my rationale for following one eating regimen or another what I eat is to enjoy myself but also have mental energy”