Your binge/restrict cycle sounds a lot more like an eating disorder than fasting. I only say this because I’ve been through similar and had to take a hard look at my relationship with food. Fasting was definitely an excuse to continue my disordered eating.
As long as you’re getting the vitamins and nutrients you need while you fast, but, I don’t see the reason to go 3 days if you’re already thin and healthy, you could do a 23/1 instead, and just eat like 500 calories, or something. Minerals and vitamins are the key to maintaining this, and we have 103 in our bodies, so, make sure you’re getting most of them.