Getting your period can be a serious drag. Aside from the pain of cramps and discomfort of bloating, the stress of stepping on the scale that week is enough to leave you feeling defeated, even if you've been eating healthy and hitting the gym regularly. But before you throw in the towel altogether, keep this in mind: It's completely normal to gain weight during your period.
Here, doctors explain why period weight gain happens, how much period weight gain is normal, and how long you can expect the extra kilos to stick around.
When does period weight gain start? And how long does it last?
"It's common to begin feeling the bloat and the extra weight around your middle in the few days prior to your period," says gynaecologist Dr Angela Chaudhar. "This is because progesterone is the dominant hormone right before you get your period, which tends to cause water retention."
The good news: your weight should be back to normal by the time your period ends.
Ugh! So how much weight do you gain on your period, exactly?
You might feel like you're gaining a pound an hour on your period, but overall weight gain should be minimal, says gynaecologist Dr Monica Svets. Some women will gain more than others, but a good rule of thumb on average is that you can expect to gain anywhere from 0.5-1.5kgs during your period (though some women may see an uptick of up to 3kgs). If you think you may be gaining too much weight, see your doctor. It could signal an endocrine or kidney issue if your body is retaining too much water at once.
The 4 most common reasons you gain weight on your period
The hormonal changes going on before and during your period can greatly impact weight changes. To understand how your weight can change, it's important to know how your menstrual cycle operates in general.
"A few days before menstruation occurs, we ovulate," says Dr Svets. "Fluctuations in hormones start. Progesterone, which has been building up over the luteal phase [the timespan immediately after ovulation until the day before your period] drops along with oestrogen right before you menstruate. The symptoms women will experience, like weight gain and fatigue, appear right before this sudden decrease in hormones." Oestrogen and progesterone get blamed as the two major female hormones involved in the menstrual cycle (and the quick drop of both is why you suffer from PMS before your period), but other hormonal factors are involved which directly affect your weight.
1. Hormone changes make your body retain water
It's not just a feeling—you are retaining water during your period that can lead to weight gain.
"Fluctuations in a hormone secreted by adrenal glands called aldosterone leads to water retention," says Dr Svets. "Aldosterone helps water management, how much liquid we put through our kidneys, and helps with fluid management." Aldosterone levels increase during the luteal phase and decrease during the follicular phase (the days you’re actively menstruating), which leads to an increase in water retention. (A 2017 study published in Obstetrics and Gynecology International actually found that the first day of a woman's period is the day the most water is retained.)
Progesterone also plays a big role in why your body retains water, according to Dr Chaudhari. "Progesterone can lead to water weight gain by allowing fluids to leak out of your blood vessels into surrounding tissues. This retention of water in your tissues can lead to the temporary weight gain around your period and will dissipate on its own after your cycle begins and your hormone levels drop," she says.
Period weight gain tip:
It may seem counterintuitive but drinking more during your period actually helps keep water retention at bay. "Having more fluid in your vessels where it belongs leads to better hydration and flushing out of your system,” says Dr Chaudhari. Aim to drink two litres of water per day to help keep bloating and weight gain stabilised.
2. You're (trying) to fight off serious food cravings
It's no mystery that women grab for chocolate and comfort foods (hello, mac and cheese!) more during their period than normal, but science still doesn't know exactly why cravings happen so strongly around your period.
"The exact reason for the cravings is unknown, but we know high progesterone levels seem to contribute. Similar to early pregnancy when progesterone is our dominant hormone, women just before their period experience more desire to eat foods that are higher in fat, salt, and sugar," says Dr Chaudhari.
You may think these cravings are hard-coded into our hormones (or lack thereof), but that's not necessarily the case. A recent study published in PLOS One found that 50 percent of women in the US crave chocolate before their period, while only 17 percent of foreign-born counterparts found themselves with the same craving, proving that the types of food women crave are more based on culture (and marketing).
"Progesterone may increase appetite, but what we choose to eat is more cultural," says Dr Svets. "Do we need chocolate? Is it a physiological need? Probably not. Salty chips, physiologic need? Probably not. The body doesn’t necessarily need these things, but with an increased appetite and fatigue, women may be looking for comfort food."
Those treats can add up. "Many women change their diet around their period, giving in to those cravings. A diet with too many refined sugars can lead to a quick drop in sugar, and therefore, energy levels," says Dr Chaudhari.
Period weight gain tip:
Satisfy your cravings in a healthy way. Make peanut butter protein balls for something sweet that's packed with protein and stock your fridge with fruit if you know you're likely to have a sweet tooth. And if you need chocolate (because, let's face it – sometimes an apple just isn’t cutting it), stick to dark chocolate that's at least 70 percent cocoa.
3. You're more likely to skip your workout
Let's be honest: it's just harder to get motivated for the gym during your period. Fatigue is real, and it may keep your from hitting the gym.
"Your hormone levels all drop at once at the start of your period, so it is common for women to have lower energy levels as part of their normal fluctuations," says Dr Chaudhari.
The combination of being less active and indulging in extra treats may make an impact on your waistline. But the benefits of exercise during your period prove you should try to push through the urge to skip. Studies have shown that exercise can reduce PMS symptoms and the pain of menstrual cramps. Plus, if you feel like you're gaining weight, whether during your period or any other time, they only way to remedy that feeling is to start moving.
Period weight gain tip:
Make sure to move a little bit every day. If you can’t muster up the motivation to do your usual routine, here's how you can walk a kilometre withouth leaving home.
4. Your GI tract is out of whack
"Your hormones (especially progesterone) are the culprit for bloating and gas," says Dr Chaudhari. You period can also lead to changes in your bowel movements, leaving you feeling irregular. "Normal hormonal fluctuations can lead to constipation and increased gas around your periods and usually resolve a few days after your period begins."
Period weight gain tip:
The best way to combat constipation and tummy troubles is to increase your water intake, move more, and eat lots of fiber, says Dr Chaudhari.