There are many different ways to IF and this is another variation. With the benefits of fasting becoming more well-known, I don't know why people still poo-poo the idea. Maybe if more of us fasted now and again, we wouldn't be here.
Going without or greatly minimizing food intake for a couple days a week is what a lot of naturally thin people do.
Some of us have bodies who get used to what we're doing very quickly and calorie-cycling works. JUDDD is one of the better known versions and there are tons of success stories. I'm on another forum where one woman has lost over 100 lbs. and she looks fabulous. There are several more who have lost upwards of 50 lbs. or more. They haven't lacked for nutrients on a down day - it's amazing what you can feed your body on 500 nutritious calories.
If you add the calories on your Up Day and Down Day calories, divide them by 2, you get a typical daily calorie intake number. Mine is 1249. I'd much rather divvy it up and have one day where I can eat what I want heartily (and no not "junk"), then have to deal with that small number every day. As for the smaller deficit, the body needs a pretty wide deficit for it to work. I had a hard time seeing any loss and once I counted my calories for a few Up Days, I saw I wasn't eating enough. Once I ate up to those, the weight began coming off.
Intermittent fasting is becoming such a well-known benefit and it really makes me shake my head when people continue to say what a bad idea it is or gasp at 500 calories. And it might be for those who have eating disorders. But for the majority, IF can be a huge benefit.
I'm not a success story yet. It has worked for me in the past but I let myself get derailed. My body has changed since having major surgery last year and it's holding on to every flipping pound, sadly!! I'm mixing JUDDD and 5:2 in hopes of further shaking up my body.
Egads, I hope I don't come across like I think I'm some expert or something - not my intention.
I'm struggling to lose weight like the rest of us. I just felt a need to throw in my penny thoughts because there are many, many people doing some form of IF and having great success.