I do it for 3 weeks only, but 20 years ago I did not eat on Thursdays at all. I did not have a name for that diet or anything. I just knew, that if you have a 3 meals cycle of eating a day and your organism gets used to that and to 2200 calories a day if you look at longer period of time, and eat 5 days a week and instead of 15400 calories a week just 11000 calories it will also get used to that.
After a month, my organism got to the new rhythm and I was not hungry on Thursdays. Actually my stomach did hurt, the first Thursday I ate at the end.
Maybe the beginning will be a little hard, but than it will just be as it is.
I do not count the calories now. I eat breakfast as I like it, and nothing more those two days. I lost 2 kg in the 3 weeks. I am also sorry to eat sweets the other days, because I want to respect my fasting days. For now I feel happy.
Another think is, that if you look at this diet as the way of life, that you will not be impatient. I want to do 5:2 until I loose half of me today. Than to keep it I will add light supper to that or go 6:1. I do not know today. I just know I plan to do it for next few years for sure, and never go back to what I have been eating before.