The keto diet is pretty forgiving. I did it for 2 weeks and aside from missing snacking and being annoyed that I had to check the carbs on everything (apples have a ton of carbs apparently-- who knew?) it was easy. All my normal meals are frying some meat in oil, plus steamed or fried veggies, plus a carb like noodles or rice. I just stopped making the carb and went heavy on the olive oil and voila. I didn't notice too much difference, energy-wise, as in I didn't notice that I became a different person full of energy like I see in some positive testimonials. So I haven't continued it. But those first few days after I went back to eating carbs I sure did notice the hit to my energy in the hours after eating them.