My understanding is that we want to have good metabolic flexibility, where it is easy and normal for our bodies to use stored energy (fat cells) instead of the

My understanding is that we want to have good metabolic flexibility, where it is easy and normal for our bodies to use stored energy (fat cells) instead of the glucose/glucogen (carbs) thing. Some people achieve this via low carb diets and keto, but intermittent fasting is also a good way to do it. I've been on the one meal per day thing for years. I'm approaching 50 and have a physique comparable or better than most 20 year olds. So while it's a data point of one, I can say that it works very well for me and I enthusiastically recommend it for multiple reasons, not just bodybuilding.