Leangains style fasting didn't work for me. My body temperature was ridiculously low in the mornings and I started to feel cranky and depressed all the time. It was pretty bad.
I fixed it by following the
'bulletproof' intermittent fasting protocol instead. My body recomp and fat loss seems to be about the same amount as when I was doing Leangains and my strength gains have increased, but I don't experience the crippling brain fog or the lack of energy that I was feeling with Leangains.
With bulletproof IF, you drink two mugs of coffee with 30g of butter and a tabletspoon of MCT oil added to it when you first wake up in the morning. My six hour eating period is from 2pm til 8pm, so I don't eat again until 2. I workout about 1230 on workout days.
I stick to the Leangains style carb cycling and macros except with the coffee in the morning.
I know a lot of people don't experience lethargy or brain fog on Leangains, which is awesome, but if you do, bulletproof IF is a really great alternative. The bulletproofexec site seems like a complete scam but, surprisingly, the stuff he recommends actually works really well.