term solution.

As others have said you are basically starving yourself for extended periods of time.

I would challenge you to find one study that says going without food for 72+ hrs is a healthy weight management solution. I'm a huge fan and supporter of intermittent fasting but extended periods are likely reducing muscle mass to unhealthy levels...ie(skin and bones).

I would think taking a reduced caloric intake is a much safer and easier process. There is plenty of science that says this is the most logical way for weight loss.

I would say most people fail at weight loss because in reality its a long drawn out process and people just don't want to take the time. Healthy weight loss long term is <2lbs a week. For someone trying to lose 80+ lbs that can be over a year. People don't have the discipline to do it. The people that do usually keep it off because they have the discipline to loose it in the first place. There is a reason the weight loss industry in a billion dollar one.