Day 7 is our snack day. The reason you start on a Sunday is so the snack day can be Saturday night. The idea is to have a reward day but still you have to keep it reasonable. At least keep under your average calories consumption. If you are 198 lbs / 90 kg then you should still not exceed 3000 calories. Best you keep 500 calories below. No need to be super counting everything but you still do not want to go mad.
Do not be surprised if you drink a lot of water and eat salty things that you start the next day 1-2 kg higher especially if you drink a lot of alcohol. Do not worry it is just fluid retention. IF you really gained a lot of weight the morning after. Do a cardio exercise on day 8 a few hours after breakfast or lunch when you have had some carbohydrates again and the sugar in your blood is higher.
If you really want a small pizza then we recommend justeat.com
IN GENERAL NEVER SNACK 2 DAYS IN A ROW IN THE FUTURE ! 1 DAY YES, 2 DAYS->HABIT