Some gain and lose water weight quicker than others. Some that were eating a very poor, high sodium diet prior to weigh in and then cleaning it up can lose alot of scale weight quickly. Females can have hormonal issues that can affect body weight 4% in a few days. That will even out though, as this group will have the same issue 28 days later ;-)

It will all balance out in 28 days, dont be discouraged!