The usual premise of these advertisements is that you can lose a tremendous amount of weight very quickly and look great in no time.
Most protein is in muscles, and most fat is in fat cells.
There is much more water in muscle tissue than in fat tissue. You probably think that to lose weight, you need to burn up more calories than you eat. This is not exactly true. You can lose weight without burning any extra calories if your weight loss is all water. Some weight-loss products bank on this and claim they reduce bloating or water retention.