It has long been found that very thin ballerinas or gymnasts often delay menarche. The incidence of amenorrhea and less menstrual flow is much higher than that of normal people. Studies have shown that the minimum weight of a certain height represents the critical lean/fat ratio, which is necessary for menstrual cramps and maintaining a regular ovulation cycle. When women lose 10%- 15% of their body weight, that is, about13 of their body fat, menstrual disorder or amenorrhea will occur.
In the past century, the age of menarche for women has gradually advanced. According to statistics, in western countries, the age of menarche starts from 1850, almost once every 10 years, four months earlier. For example, in Norway, which is located in northern Europe, the average age of menarche for girls in their forties in 19 was 17, but a century later, it was advanced to 13.5. Compared with the two surveys in Beijing (1963- 1964) and 1979- 1980, 16 was 0.8 years earlier.
You should gain weight, or you will suffer from menstrual disorder.
To sum up, it can be considered that the age of menarche is advanced because of the improvement of social, nutritional and health conditions, so that the critical weight required for menarche is reached in advance. If you pay attention every day, you may also find that moderately overweight girls reach menarche earlier than thin girls; Malnutrition can delay menarche. Anorexia girls whose weight is below the critical weight often lead to amenorrhea.