Recommending intermittent fasting to adolescent girls, especially those with obesity or overweight, is uncertain due to unknown risks.

“So, from an evolutionary perspective, you would think that would be selected against. But, you know, and it's not clear. I guess, I don't know enough about anorexia nervosa. But, you know, back in human recorded history, is anorexia nervosa even common? Or is this something that has arisen more as girls are more conscious of their body image and so on? And, you know, therefore, there's this psychological factor that I don't know if that's something that... I guess what I'm saying, it doesn't make sense to me that anorexia nervosa would be something that will not be strongly selected against during evolution. And these girls often, they usually quit cycling, too. You know, so, yeah, I guess we just don't know. On the one hand, intuitively, I'd say, it won't be a good idea to recommend this to adolescent girls. But if they're with obesity or overweight, I don't know. We just don't know. I think that seems like maybe okay, but we just don't know.”