I have had my best workouts completely fasted! Once you adapt to training in the fasted state you get a boost of energy and strength. I think this goes back to stimulating the sympathetic system (fight or flight). In addition Fasted training has been shown to increase insulin sensitivity and improve nutrient partitioning. This means that your body will be more efficient at directing nutrients into muscle cells and away from fat stores. Thus training in the fasted state makes the subsequent meals more anabolic. This is why I absolutely love intermittent fasting for fat loss and building muscle. With that said pre- workout protein is beneficial at increasing protein synthesis, elevating metabolism and reducing muscle breakdown. Therefore I recommend 10 grams of BCAA before an intermittent fasting workout.
The only draw back you will see is for those who do have high activities or are involved in lots of sprinting type exercise. Although a few will find they feel fine, even have more energy on a high fat/moderate protein diet, most of the time carbohydrates are the best source of fuel for these activities. That isn't that big of a problem though, it just means that that person should instead look into doing a TKD instead of a CKD.
How often you eat is also up to your personal preference. "For most people, I recommend three to four meals per day with a few healthy keto snacks in between," says Dr. Axe. "This ensures that you're getting a good mix of protein and fat all day long to keep you feeling energized and satisfied." That being said, he encourages people to listen to their bodies and tune in to when they're truly hungry. "If you find that you feel better eating five to six smaller meals spread throughout the day, do what works best for you."