Want to get into intermittent fasting mainly for the cognitive benefits; advice on where to begin?

And is there potential for harm if I'm a 120 lb, 5'4, 19 yr old female with a fast metabolism as is?Thanks, new to this so don't downvote to oblivion :) via /r/intermittentfasting http://bit.ly/2SrN6Li https://ift.tt/eA8V8J