5 reasons you experience weight gain during your period

Published September 25, 2019

What causes weight gain during menstruation?

From fluid retention, constipation to PMS, there are several factors that affect your weight during menstruation. For most women, weight gain during menstruation is only temporary. Maintaining an overall healthy lifestyle will keep those extra kilograms from becoming permanent.

1. Fluid retention

Feeling bloated is a common complaint during the menstrual cycle. Elevated levels of the female reproductive hormones estrogen and progesterone lead to a shift in the body’s set point for sodium and cause fluid retention. “This may be the most noticeable to women during the second half of their menstrual cycle, when both estradiol the most potent and common of the three estrogen hormones and progesterone levels are at their highest,” says Heather Huddleston, MD, associate professor, division of reproductive endocrinology and infertility, at the UCSF Center for Reproductive Health.

To keep fluid retention at bay, try to avoid salty foods during the second half of your menstrual cycle. Try to avoid diuretics, says Amy Stephens, MD, a doctor of obstetrics and gynecology at the Cleveland Clinic. “In severe cases, some women may be prescribed them, but that should be something done in conjunction with your gynecologist,” says Dr. Stephens.

2. Constipation

Your period affects how well your gastrointestinal tract works to push out waste from your body. “Progesterone causes some relaxation of smooth muscle, leading to a reduction in gastrointestinal motility, which may lead to bloating and constipation in some women,” says Dr. Huddleston. To reduce both, increase the amount of fibre in your diet, particularly in the second half of the menstrual cycle, she suggests.

3. Food intake

Progesterone plays another weighty role during the second half of the menstrual cycle. It increases appetite, which may cause you to eat more.

To keep from overeating, gravitate towards foods that provide lots of essential nutrients and will keep you feeling fuller for longer such as fresh fruit and veggies, eggs and lean meats.

4. PMS

For most women, their monthly “cycle” starts with at least one of the host of symptoms known as premenstrual syndrome, or PMS, about one or two weeks before their actual period begins. Bloating, food cravings, and weight gain are among the most common symptoms. A study of 259 healthy women with regular menstrual cycles showed significant increases in appetite, protein intake, and total cravings, including those for chocolate, sweets, and salty flavours during the luteal, or premenstrual phase before menstruation begins.

Experiencing depression or anxiety are also hallmarks of PMS, which is thought to be caused by cyclic changes in the brain chemical serotonin. “For some women, these mood symptoms can also lead to increased food intake,” says Dr. Huddleston. About 3 to 8 percent of women may experience a severe form of PMS known as premenstrual dysphoric disorder (PMDD), according to the American College of Obstetricians and Gynecologists. Food cravings or binge eating are some of the symptoms of PMDD. See a health professional if you experience significant depression or anxiety during PMS, says Dr. Huddleston.

To offset the serotonin drop during PMS or the second half of your cycle, increase exercise as it is is known to boost serotonin levels and focus on consuming healthy, nutrient-rich foods.


If you experience irregular periods and weight gain, it might be worth a checkup with your doctor. Polycystic Ovary Syndrome, or PCOS, is an imbalance of reproductive hormones that causes metabolism problems. It affects 1 in 10 women of childbearing age.

In obese women with PCOS, losing weight may help regulate their menstrual cycles. “Fat itself can produce estrogen which can cause hormonal imbalances that can affect the cycle,” says Dr. Stephens. “Irregular cycles do not cause weight gain. Weight gain can cause irregular cycles.”

For most women, weight gain during menstruation is only temporary. Maintaining an overall healthy lifestyle will keep those extra kilograms from becoming permanent.