When you fast your body get automatic into ketosis after few days. So if you are already on keto you just skip waiting for your body to get into ketosis. For me farting works even better when I’m on keto because of those reason.
Keto is great and was easy for me to follow. Steak, eggs, real butter on everything and vegetables. Combined with fasting I lost the weight I wanted to and more. But, my cholesterol shot up. I am now a thin vegan and I usually fast 18:6 daily.