How much weight can you lose on Danish diet?

I have a very similar situation.

My friend was also on this diet. I was very supportive and everything. I offered to cook for him and even to start following his eating habits, but he refused and said there is no need for that. He was very determined to stick up to this diet. But that lasted only a week. After that he started eating whatever he wants once in three days, and later on ‘’once in three days’’ transformed to ‘’once daily’’.

If he had stuck up to it though, he would probably be able to lose 22 pounds by the end of day 13.

I am very familiar with everything you said. My friend is very stubborn and knowing that, I thought he won’t give up on his goal. But I wasn't right. Every single time we went out on a dinner I try to be a good friend by ordering something tasteless so that he doesn't have to watch me eating all the delicious stuff while he is on a diet. But he doesn't even appreciate that and he orders 2-3 things from the restricted list a minute later. And then after he finishes with eating, he feels guilty.

So I am aware that I cannot judge the efficiency of this diet by looking at his example.
If there is anyone who actually was disciplined while following this diet, please let me know how much weight did you lose?

My sister was on this diet. She had weight problems ever since she was a little child. Now she is in a sensitive period of her life and her pounds are starting to drag her self-confidence and her self-esteem down. She decided to try this diet very spontaneously, she heard about it from some girl in her school. We supported her, which I think meant a lot to her. And by the end of day 13 she lost 17 pounds. It was very hard, she practiced every single day, twice. She was very disciplined. I think she pulled off the maximum of this diet.