This feels like a flippant, uninformed comment. When you don’t eat those for a 2-3 day window your body ramps up energy production through stored fat. So I’d say you still have energy.
I've tried both eating a little often and a lot very little and from the experiences of me and everyone I have ever spoken to in the flesh about this, it really is as simple as "more energy when you eat more".
Fasting won't give you mountains of physical pep. Sure, there is that golden time after you have done it for a while where you get great mental clarity and you feel good but you will not be voluntarily running laps or pushing your absolute peak weight in the gym.
That barrier is something you'll always feel, even if you're not pushing the limits. The fact of the matter is that barrier is closer when you are fasting.
Stored fat in a teenager going through a growth spurt??
Their bodies (and brains) are doing a lot more developing than just growth spurting, which is why such a teenager can eat huge portions[0] per day and not put on any fat at all. Because their bodies use it all up, because of all the transformations and puberty things going on.
I would suggest, in that stage, just giving the body everything it craves, and worry about the benefits of fasting later.
[0] obviously doesn't hold in parts of the world where these are considered "normal" portions.
I'm not responding to this because it seems like you really don't realize how vapid your comment is. If you want to learn more, please open a book, don't read internet forum research.
Fasting won't give you mountains of physical pep. Sure, there is that golden time after you have done it for a while where you get great mental clarity and you feel good but you will not be voluntarily running laps or pushing your absolute peak weight in the gym.
That barrier is something you'll always feel, even if you're not pushing the limits. The fact of the matter is that barrier is closer when you are fasting.