I usually fast Mondays, Wednesdays, and Fridays, it helps that I'm usually too busy to eat at work too so I don't really have the time to get hungry. I limit myself to water and unsweetened tea for the day and I do lighter workouts the days I fast. I don't typically like to fast on weekends because that's when we have the most family get togethers or holiday celebrations. If you're looking into starting it then just start with one day a week where you keep your calories below 500 and then slowly work from there.