It can be good for you, but it's too prone to problems. It's likely to cause an eating disorder, malnutrition, or poor eating.
The basic idea behind it is you eat small amounts of fruit, vegetables, and protein throughout the day. Then, at the end of the day, you eat until you are full.
Think of it more like a hunters diet. You spend the day hunting, eating fruits and berries and herbs as you hunt. At the end of the day, the hunt finished, you eat your catch.
It's almost like binging and purging - except now it's starving and binging. It can work, and I'm sure it has worked for a lot of people, but it's also been bad for a lot of people. That's the problem with unconventional diets -- there's a reason they're unconventional.