You might be ok, as long as you adjust your calories properly, but your body is also still in development. You require more calories, and denser, more nutrient rich foods, than you will as an adult.
I’d say a better way to go is to manage healthy habits. Get into the habit of not eating a lot of sugar, of watching your calories, paying attention to labels. Those are things that will come with you into adulthood that set healthy habits for life.
I’m not a Dr or nutritionist, so I really can’t say you should stop fasting. Just be careful that you aren’t accidentally starving your body of something it needs.