Hate to break it to you, but the concept of negative calories is a scam. The amount of calories you burn digesting food is practially nil. The muscles involved have been working virtually 24/7 since the day you were born: they're very efficient. All they do is move stuff, very slowly, through your digestive tract. The rest of the work is chemical. There's no way it burns many calories at all. People who lose weight on that diet do so because they're eating a ton of fruit and vegetables and lower their overall calorie intake. They'd lose more than someone fasting because fasting causes your metabolism to hit the floor.

My personal rule: never trust anything sold via MLM.

The only way someone could lose that much weight in a short period of time would be if s/he was very overweight. The original poster was only 160 lbs.