Starvation

Starvation "diets" are one way some people to choose to try to lose weight. While this may bring momentary results, the problem is that the weight loss is not just fat; it's also water, muscle and bone. Further, the body does not get the appropriate nutrients and begins feeding on itself, which can lead to additional health problems.

Laxatives

Laxatives are one source of "rapid weight loss" used over the years. The idea is that the laxative will help you avoid absorbing the food consumed by inducing a bowel movement. The problem is that the food has already been absorbed by the time the laxative does its job. The laxative then forces food to move through the system at a faster than normal rate, which doesn't allow the body to absorb all the nutrients. The weight lost from this method is only water weight.

Sauna Suits

Sauna suits and sweat suits are another popular form of rapid weight loss. While some professional athletes wear them to make weight, they understand that it is not a way to permanently lose weight. Immediately following their weigh-in, the athletes will begin the rehydration process. These suits are designed to make you sweat, so it seems obvious that the weight lost is purely water weight.

Smoking

According to steadyhealth.com, research shows that smoking cigarettes increases metabolic rate and suppresses appetite. However, the positive effects of smoking are heavily outweighed by the negative side effects, like lung cancer and emphysema.