The side effects of low calorie dieting may be harmful because of its extensive effects on the human body.

1. Slows Down Metabolism

Lower calories results in a slower metabolism becomes because there is less for the body to burn. The slowing down of metabolism makes it harder for the body to burn fat even if there are lesser calories to work on. Severe calorie restrictions decrease metabolism by as much as 20 to 30%, which is why people on a calorie restricted diet find it almost impossible to the lose the last 10 or 20 pounds towards their optimal target weight.

2. Results to Muscle Loss

A low calorie diet always results to the loss of muscle tissue. Once the body reacts to severe calorie restrictions, the body begins to look for ways to conserve energy; since the muscle is a metabolically active tissue, getting rid of it is the body’s initial response to decrease energy expenditure. The body starts converting muscle including skeletal muscles, internal organs, even the heart muscle into glucose!

3. Increases Activity of Fat-Storing Enzymes and Decreases Activity of Fat Burning Enzymes

Rapid decreases of calorie intake results to the production of fat storing enzyme called Lipoprotein Lipase (LPL) and a decrease in the production of fat burning enzymes.

4. Decreases Output of Thyroid Hormone

Calorie reduction in results in a corresponding reduction in the output of active thyroid hormone which results to an overall decrease in the metabolic rate and fewer calories burned.

5. Weight Gain Rebound

Although a low calorie diet results in immediate weight loss, it never takes long for the body to catch on and starts conserving energy. When this happens, losing weight becomes much harder. Because no more results are visible, hunger pangs cause people to give up the diet program. As soon as they stop the diet program, weight is regained immediately.

6. Decreases Energy and Work Capacity.

Restricted calorie diets generally make you tired, lethargic and unable to work out. High levels of activity or intense workouts are crucial if you aim for long-term fat loss.