Pregnant women have had great success with the plan, and a couple of pounds of weight loss is not uncommon or unhealthy. Losing necessary body weight/fat does not happen on the plan. Following the plan as written is important, which means doing the sweating.
Losing excess water, which weighs quite a bit, can be beneficial. The body holds onto water to buffer toxins. That water becomes unnecessary excess weight that the body has to carry around with it. As you detoxify the body and eliminate toxins, the body will release the excess water. This helps to improve the health and function of all the cells, tissues, and organs.