How hard is it to eat only 600 calories on fast day? I allow 100 cal for breakfast, 250 cal for lunch and 250 cal for dinner and no snack. It takes a little bit of sportsmanship and a lot of nutritional table readings but it is quite do-able.
Black coffee and half a slice of toast with a little bit of jam would be my fast day breakfast. Salad for lunch. Thankfully there is NuPasta which, even with my favorite sauce and topping, gives a very tasteful and fulfilling dinner for around 200 calories. It is so easy I almost feel that I am cheating.
Read Part II: Intermittent Fasting II: Numbers