The standard weight of 172 girls is 67kg, and the standard weight algorithm for girls is: standard weight (kg)=height (cm)-105, and it is normal for the actual weight to fluctuate around 10% of the standard weight. If a girl is too thin, it may be due to malnutrition caused by the body, which will appear low immunity, can cause a variety of diseases, so if there is a thin situation, must be timely supplemental nutrition to regulate. If the girl is fat is also not conducive to the health of the body, too obese is very easy to metabolic diseases, if there is obesity, must exercise, diet control, through weight loss to maintain good health, reduce the occurrence of disease. In ordinary life, many girls are pursuing weight loss, think thin to look good, in fact, this view is wrong. Too fat and too thin will affect the health of the body. However, if one’s situation is special, such as during pregnancy or when suffering from a certain disease, one should follow the medical advice to maintain the appropriate weight.