My boyfriend calls this the Brian Butterfield diet (watch the youtube clip and you'll see what he means, it is very funny. Bonbonbonbons!). I suppose fasting can seem quite extreme but having done low calorie dieting before it's funny that not eating for a day can be much easier than restricting calories every day.
I don't currently track calories on feed days, generally eat quite healthily during the week and more liberally at weekends. I try to eat real, whole foods, avoiding sugar and processed foods. I do make exceptions in order to eat cake and ice cream every now and then but try to make these from scratch.
Yesterday I did my first liquids-only fast day, replacing usual dinner with a cup of miso broth with seaweed and a hot chocolate made with milk + cocoa + a bit of sugar before bedtime. (The latter probably isn't ideal because of the sugar but I don't seem to suffer any ill effects from it today.)
Today is a feed day.
Breakfast - Two boiled eggs, two slices of rye bread with a bit of butter, greek yogurt, milky coffee.
Lunch - Salad of new potatoes, iceberg lettuce, cherry tomatoes and sardines in olive oil.
Dinner - Not sure yet what to make, will decide when I go food shopping after work.
Post fast weigh in this morning - 59.9 kg which is a number I like to see!