Losing weight has its adverse effects especially when it is done rapidly. Many people do not know that when they lose too much weight in a short time, they can gain even much more back once they stop, making their latter state to be worse than the former. Rapid weight loss can also lead to excess skin tags which may latter necessitate plastic surgery.
Muscle loss could occur in the process of losing weight. The aim of dieting is to reduce weight through fat loss but if not careful, muscles will be lost in the process. This can be prevented by regularly lifting weights or doing push ups and by maintaining sufficient protein intake. Those that are on a low carbohydrate diet and are doing lots of strenuous work should increase their protein intake.
During prolonged fasting or very low calorie diet, there is reduction in blood glucose, the preferred energy source of the brain, causing the body to deplete its glycogen stores. Once the glycogen stores are depleted, the body starts using ketones as energy source for the brain. This can eventually lead to dizziness and subsequently fainting.
Other side effects of rapid weight loss include loss of sex drive, depression, irritability, prolonged hunger, fatigue, fainting spells, rashes, gall bladder disease, rashes, malnutrition, constipation (from reduced food intake), dehydration (from reduced water intake). Also we have, lowered metabolism making future attempt at weight loss more difficult. There is also the risk of developing eating disorder especially anorexia nervosa or bulimia nervosa.