Beneficial for digestion + skin problems to fast/ go on detox diet for a few days regularly? every week/ month? for teenagers and adults - different?

Variable : Fasting has a long tradition in many cultures and has many claims attributed to it. It does suit some people but by the same token some people get violently sick with headaches nausea and hypoglycemic symptoms. So I think it shd be approached with caution and a lot of motivation. No cook book recommendations can be made for different age groups. It is a very personal approach and very variable.