To achieve rapid weight loss, you'll need to modify your diet. Despite all the exercise and carefully measured healthy foods, it's not realistic for a person who isn't morbidly obese to lose that amount of weight in seven days. They reportedly feed contestants less than 1,000 calories a day for five to eight hours of training, in addition to using unhealthy tricks, such as dehydrating contestants before intervening to artificially increase weight loss figures. However, since these conditions are more extreme than your everyday life, you can do more than that.
I only need to lose about 10 pounds (if that) and I was able to lose more than four pounds during the week. Some of the heaviest male contestants who had 50 or more pounds to lose lost 10 or 11 pounds in their first week (some of which are water weight).