This results in a condition in which the person now weighs more than they did before the weight loss program or diet. They attempt to lose the weight by going back on the same diet or a similar program. This time, the weight loss is harder to accomplish, the basic metabolic rate may diminish more, and the person will eventually go off the diet and gain more weight! This is a cycle often referred to as yo-yo dieting, and, as you can see, it is a self-defeating situation.

During an extreme diet, one in which as little as two to three pounds a week are lost, the dieter can experience the loss of lean muscle mass. Lean muscle mass is the "incinerator" that burns excess calories, and its loss can only make healthy weight loss even more difficult. Additionally, with less lean muscle, the person is less likely to feel like engaging in activity which could help burn fat.

While an actual rapid weight loss "danger" is relatively small though quite genuine, the results, or lack of same, when combined with the loss of needed nutrients do not really seem worth the effort or risk. However, be aware that in the presence of some clinical conditions or while attempting to achieve rapid weight loss through extreme measures, the danger to health, and even life itself, can be quite real.