Hi, thank you for the question. Each human being is different, so does the menstrual period of every woman. On average, a menstrual cycle lasted for 28 days. Menstrual flow also can vary from 21 days to 35 days. Generally women will have regular menstrual period after their puberty.

Weight does have effect on your menstrual cycle. Overweight and underweight will cause irregular periods. Weight changes causes sex hormone changes in your body. The sex hormones in the female are estrogen and progesterone which helps to regulate the menstrual cycle.

Insufficient sex hormone production in your body can cause delay in period, causing irregular period. In fact, there are other causes that can cause irregular period, such as pregnancy, oral contraceptive pill, excessive exercises, stress, thyroid problem and polycystic ovary syndrome.

Controlling your weight within the normal range can help to improve sex hormone level and subsequently a more regular period. You may try to reduce your weight to the normal range by using the BMI charting. However, if there is any difficulty please seek help from the healthcare providers. They will provide valuable information that helps your in weight management.

In some cases, overweight woman has higher risks of developing polycystic ovary syndrome (PCOS). Weight gain and irregular periods are symptoms of polycystic ovary syndrome. Bear in mind that not every woman that is overweight has polycystic ovary syndrome.

On the other end, underweight woman can also have irregular period due to sexual hormone imbalance. In conclusion, maintaining a healthy weight is the key of having regular menstrual cycle, healthier body and sharper mind. Have a good day !!!