Weight gain is not achieved overnight, and so is weight loss. If you are losing weight, the Centers for Disease Control and Prevention (CDC) says that the safest weight loss rate is 1~2 pounds per week (about 0.5 ~ 1 kg). If it is faster than this, there is a greater possibility of health problems. A weight of 0.5kg is equivalent to 3500 calories. If you want to lose 0.5 kg a week, you can reduce your total calorie intake by 500 calories a day. In addition to calculating the calories consumed and ingested, dieters should also pay attention to maintaining a balanced diet to avoid malnutrition. Eat more vegetables, fruits, yogurt, nuts and whole grains. These foods are rich in fiber and protein, which helps to keep satiety and reduce excessive calorie intake.

1. It hurts to lose weight.

A deflated balloon will become slack and wrinkled. Losing weight quickly is like deflation. When the human body loses too much fat at once, the skin will be loose and rough, and hair loss and constipation may occur.

Most rapid weight loss methods start with a substantial reduction in calorie intake. However, if the calorie intake is greatly reduced and the energy and nutrients in the human body are insufficient, it will easily lead to temporary liver and kidney dysfunction or affect gastrointestinal function. In addition, some people will over-diet in order to lose weight quickly. Long-term dieting can easily lead to anorexia.

2. Lose weight quickly and rebound quickly

Losing weight too fast will cause a lot of loss of muscle, fat and water. Decreased muscle mass will affect the metabolic rate of the human body. After the metabolic rate of human body is reduced, as long as you eat more or exercise less, the lost fat will come back soon. Moreover, the human body has inertia about weight. After losing weight, the body's memory still stays at the previous weight, and then slowly the weight will rebound back to the previous weight. The way to fight this inertia is to lose weight slowly, and let your body adapt to your weight after losing weight.

3. losing weight quickly has an impact on health.

Gallstones: A common side effect of losing weight too fast is gallstones. About 12%~25% people who lose a lot of weight in a short time suffer from gallstones. Although gallstones are not life-threatening, patients often feel nausea and severe abdominal pain. In severe cases, they may need to have their gallbladder removed.

Liver problems: losing weight quickly may also lead to liver damage. Some researchers investigated obese subjects who used dieting to lose weight quickly. At the beginning of the study, the liver indexes of these subjects were within the normal range, but after 4~6 weeks of dieting, the liver examination results of these subjects were slightly abnormal.

Electrolyte disorder: The symptoms are different according to the electrolyte the patient lacks. Generally speaking, it includes fatigue, dry mouth, decreased taste, nausea and vomiting, dizziness, irritability and so on.