Most of the time, if you cut through all the fluff, quick weight loss diets are usually just low-calorie diets with some being very low in calories.
VCLD’s often result in a good deal of water weight loss at the beginning, which can cause the illusion of fat loss. While this can be good motivation for making further effort, many people on rapid weight loss diets get frustrated when that trend doesn’t continue.
Other diets may promote quick weight loss in the beginning, but then advocate slow and steady weight loss as the diet continues. This is a much more realistic approach to how losing weight actually occurs.
Metabolic Slowdown: Diets really low in calories can potentially stall the metabolism leading to an even more difficult time losing weight. Dieters must support their metabolism and exercise while maintaining a safe calorie deficit to avoid this.
Malnutrition: Because many quick weight loss diets eliminate food groups and are drastically low in calories, they can leave you malnourished, which can lead to other health problems.
Yo-Yo Dieting: Quick weight loss tends to contribute to yo-yo dieting. It is unhealthy for a person’s weight to continually fluctuate back and forth.
Frustration: Dieters often gain the weight back and become frustrated with dieting and give up altogether.
Loose Skin: Losing weight quickly leaves dieters more prone to loose and saggy skin, which sometimes has to be surgically removed. This is often seen in those who underwent gastric bypass surgery.
Eating disorders: Because of the nature of most quick weight loss diets, they can contribute to eating disorders and an unhealthy relationship with food. People begin to see foods as good and bad and feel guilty when they eat the “bad” ones.