You can do proper alternate days but I personally (and I think most people on here) do 3 DownDays to 4 UpDays! My downs are Tu Th & Su but most people do Mo We Fr so the can have the weekend up days!
I started on shakes for my DownDays but I'm now starting for have soups and little meals which are more filling, lots of suggestions on here!
I really hope you enjoy it as much as we all do! And maybe join us in our October challenge thread!
Hope I've helped x