I think things like that are great to try to drop weight, fast, but don't work for the long run.
When I was in the Navy, an officer, I had a pretty soft job. No PT. I had to attend a school, and in the school they do a height/weight/body fat on day 1. About 5 weeks out , realizing my uniform was a wee tight, I got on the scale. I was about 12-15 pounds over where I needed to be. I did something like this (basically same thing, different company) and lost 20 pounds in 30 days. Second week in the school, I gained about 10 back but was moving more and eating better.
Do it to drop weight, fast, then get into a sensible eating plan and exercise routine.