Crash diet is an instant weight loss diet, in a short period of time.  However, this crash dieting does not benefit to the body, rather leads to many health problems. Crash dieting is not a healthy way of losing weight. Here are few long term and short term effects that can be expected from crash dieting.

Nutrition deficiency: The body gets deprived of essential nutrients like carbohydrates, calcium, proteins and minerals. Malnutrition leads to weakening of immune system, development of gall stones, hair loss etc.

Eating disorder: Crash diet develops many eating disorders which may lead to late night food cravings, anorexia, etc

Osteoporosis: Women are at risk in developing osteoporosis during the menopausal period. Crash dieting is prone to weakening of bones due to calcium deficiency.

Muscle and tissue loss: The fat stored in muscles get burnt instead of calories. This leads to muscle and tissue loss surrounding the vital organs like brain, liver and kidneys.

Early aging: Crash diet speeds up the process of aging. The symptoms are saggy skin and wrinkles on the face. The skin loses its elasticity.

Physiological effect: Crash diet causes mental and emotional stress. These dieters go into depression that leads to other complications like mood swings, tiredness, lack of concentration, loss of confidence, lethargy, dizziness, irritability etc.

Heart problem: Repeated crash dieting can enhance the risk towards heart attacks.

Low metabolism: Lack of calories in the diet leads to low metabolism.

Weight gain: Due to the change in the metabolism during a crash diet, the body loses some weight initially, but regains the lost weight rapidly.