Great piece! I'm almost at a decade of IF as well and it works for me. I feel sharper and have more energy through the morning. In regards to the crash you talk about I have found if I wait too long like past noon or more than 18 hours then crashes are more common. IF seems to have made me more sensitive to sugar as well. Even a glass of juice with no added sugars can make me crash. IF is natural! From an evolutionary POV we had to look for food or hunt food and often went hungry for much longer. That's how we evolved. It's not natural for our bodies to wake up and scarf over a 1000 calories in simple carbs and sugar and then sit at a desk all day. That said, if I'm going to be surfing I eat breakfast, or if I'm camping I'm having bacon and eggs cooked over the fire before I go fishing.