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During your period, it’s normal to gain three to five pounds that goes away after a few days of bleeding.

It’s a physical symptom of premenstrual syndrome (PMS). PMS includes a wide range of physical, emotional, and behavioral symptoms that affect women several days to two weeks before their period.

These symptoms are caused by the hormonal changes during the menstrual cycle.

PMS is very common. More than 90 percent of women who menstruate experience PMS.

Let’s look at a few reasons why women often gain a few pounds during their period.

Weight gain and that bloated, sore feeling in your abdomen are common symptoms during your period. You might feel this way for a number of reasons.

Hormonal changes

Hormonal changes can cause weight gain by increasing water retention.

In the days before your period, estrogen and progesterone rapidly decrease. This tells your body that it’s time to begin menstruation.

Estrogen and progesterone also control the way your body regulates fluid. When these hormones fluctuate, the tissues in your body accumulate more water. The result is water retention, or edema.

Water retention may cause swelling or puffiness in your breasts, stomach, or extremities. This increases body weight, but not fat.

Water retention is a common PMS symptom. It affects 92 percent of women who menstruate.

Bloating

Period bloating or stomach cramps can make your clothes feel tight and uncomfortable. This isn’t true weight gain, but you might feel like you’ve gained a few extra pounds.

During your period, hormonal changes can increase gas in your gastrointestinal (GI) tract and cause bloating. Water retention in your abdomen may also lead to bloating.

Bloating can be described as feeling tight or swollen in your stomach or other parts of your body.

Stomach cramps can also cause the sensation of weight gain. These cramps are caused by chemicals called prostaglandins that are released by your uterus. Prostaglandins make your uterus contract and shed its lining. This causes abdominal pain during your period.

Bloating may start five days before your period and continue into the first few days of menstruation. Stomach cramps, which begin one or two days before your period, can also last for a few days.

Food cravings or overeating

The hormonal changes during your period can also make you overeat.

In the week before your period, progesterone levels increase. Progesterone is an appetite stimulant. As progesterone rises, you might eat more than usual.

Estrogen also regulates serotonin, a neurotransmitter that controls mood and reduces appetite. When estrogen drops right before your period, so does serotonin. The result is a bigger appetite.

Low serotonin can also increase sugar cravings because high-carbohydrate foods help the body make serotonin. If serotonin is low, the brain craves more sugar. Eating high-sugar foods can increase your calorie intake and lead to weight gain.

Your metabolic rate fluctuates during your menstrual cycle, so when it rises — and your body is burning more calories — you might have a bigger appetite and crave high-calorie foods.

Gastrointestinal issues

Throughout your cycle, hormonal fluctuations can lead to GI issues like constipation, diarrhea, and abdominal pain. The discomfort and bloating in your stomach can make you feel like you’ve gained weight.

Progesterone increases a week before your period. This impairs intestinal muscle contractions, resulting in slow digestion and constipation.

As your period begins, your uterus releases prostaglandins. Prostaglandins cause muscle contractions in the uterus and gut. You may have pelvic and abdominal pain.

Prostaglandins can also cause diarrhea by disrupting electrolytes and fluid balance in the small intestine.

It’s common for healthy women to have GI issues before and during their period.

Decrease in magnesium

When your period begins, magnesium levels gradually decrease. This drop can provoke sugar cravings and contribute to weight gain.

Magnesium is a mineral that regulates your body’s hydration status. Low levels of magnesium can cause dehydration.

However, dehydration can mask itself as hunger. It can also make you desire sugary foods when you’re just thirsty.

Eating high-sugar foods can contribute to weight gain.

Skipping workouts

When you have bloating and cramps, you might be more likely to skip exercise. This can contribute to weight gain, especially if you have increased hunger or cravings.

A week before your period, estrogen and progesterone both increase, causing fatigue and low endurance. It might feel uncomfortable to exercise as it gets closer to your period.

In addition to weight gain, you may have other physical and emotional symptoms during your period. These changes may show up with or without weight gain.

Possible symptoms include:

You might experience different symptoms each month or as you get older. Every woman is different.

More than 90 percent of women experience some combination of these symptoms.

It’s possible to reduce water retention and bloating during your period through home remedies, lifestyle changes, and medications.

You can:

  • Drink more water. It sounds counter-intuitive, but staying hydrated can reduce water retention. Your body will conserve more fluids if you’re dehydrated.
  • Stock up on healthy foods. If you’re prone to cravings, keep nutritious options handy. Try eating foods like fruits or protein bars when a sugar craving strikes.
  • Take diuretics. Diuretics are pills that reduce water retention by increasing urine production. Ask your doctor for a prescription.
  • Take magnesium supplements. Make sure to check with your doctor before taking any supplements. But, if you get the go-ahead, magnesium may decrease:
    • water retention
    • bloating
    • sugar cravings
    • emotional symptoms
  • Keep moving. You can reduce fluid buildup by walking and moving around. Exercise will also make you sweat and get rid of excess water.

By practicing healthy habits throughout the month, you can prevent weight gain or water retention during your period.

Here’s what you can do:

  • Exercise regularly. Regular aerobic exercise can lessen symptoms during your period. Aim for 30 minutes of exercise each day.
  • Stay hydrated. Drink enough water throughout the month. This will prevent your body from conserving fluids.
  • Reduce salt intake. Eating too much sodium will increase water retention. To decrease your salt intake, limit or avoid processed foods.
  • Skip caffeine and sugar. Foods and drinks with caffeine and sugar may worsen bloating. Avoid these foods two weeks before your period.
  • Avoid foods that give you gas. Stay away from these foods throughout the month, not just when you have symptoms.

It’s normal to gain about three to five pounds during your period. Generally, it will go away a few days after your period starts.

Period-related weight gain is caused by hormonal fluctuations. It may be the result of water retention, overeating, sugar cravings, and skipping workouts due to cramps. Period bloating and gastrointestinal issues might also create the sensation of weight gain.

To ease water retention, stay hydrated and reduce salt intake. Move around and get regular exercise. You can also take diuretics for water retention or magnesium for bloating.

If you have severe cramps, abdominal pain, and bloating during your period, talk to your doctor.