Low-Calorie, Rapid Weight Loss Diets

Many diets offer rapid weight loss, promising to shed five, ten, or fifteen pounds in just a week or even a day. Examples of these diets, such as the Hollywood Diet, The Three Day Diet, and the Slimfast Diet offer meal-replacement products or low-calorie regimens. The common feature between these diets is that they all have too few calories in their daily menus to provide adequate nutrition. This means that most of the rapid weight loss experienced will be dehydration. When too few calories are being eaten, the body begins to burn glycogen, which is stored with water in the muscles and liver. As glycogen burns, it produces rapid weight loss which can only be short-term. As soon as caloric intake increases again, the body will work to restore these first-defence reserves without providing the real long-term benefits which dieters are looking for.

In fact, research has shown that low calorie dieting, and especially very low calorie dieting (defined as 1000 calories per day or less, also known as 'crash' diets) intended for weight loss can have the opposite of the intended effect. Highly restrictive dieting regimes can effectively tell the body that it is starving, which causes metabolic rates to slow, leading the body to conserve more fat over time. For those who are used to 'yo-yo' dieting, a cycle of continually gaining and losing weight, the body will adapt to such regimes and can store more fat over time in anticipation of the next weight-loss cycle. Weight cycling can cause depression, leading to people feeling as though their diet plans have failed; however, it is their body's natural response to short-term, self-imposed starvation or semi-starvation. Weight cycling can take on addictive properties, reduce sex drive, cause fatigue and irritability. It is never recommended that people try to lose weight quickly. It causes a loss of muscle tissue as well as fat, and can lead to the development of gall stones. As a general rule, if the diet is unsustainable, then so is the weight loss.