Why Do You Really Gain Weight on Your Period?

What Causes Weight Gain During Your Period?

Gaining a few pounds during your period is totally normal— it’s not about fat. Here’s what’s going on behind the scenes.

Hormonal Fluctuations

Hormones are the big players here. 

Right before your period, estrogen and progesterone levels drop fast. This sudden change tells your body to hold on to extra water—kind of like a sponge. 

That’s why you might feel puffier around your stomach, breasts, or even your hands and feet. It’s called water retention, and while it’s annoying, it’s not permanent. Once your hormones settle, that extra water weight will flush right out.

Bloating and Gastrointestinal Changes

Bloating is another unwelcome visitor during your period. Hormones can slow down digestion, causing your stomach to feel full and tight. 

Gas buildup or even constipation might make matters worse. 

And let’s not forget cramps—those annoying contractions in your uterus can leave you feeling heavy and uncomfortable. It’s like your body is putting on a show, and you’re the unlucky audience.

Food Cravings and Overeating

Craving chocolate or devouring an entire bag of chips in one sitting? Thank your hormones for that too. 

When serotonin levels drop (that’s the feel-good hormone), your body starts screaming for quick fixes like sweets and carbs. These foods give you a serotonin boost. 

“If you give in to those cravings and you're eating a lot of salty foods your body's gonna retain water and you're gonna feel bloated and you're gonna notice on the scale that you've gained weight. It just happens…”, says Dr. Holly Mehr MD, MSEd, FACOG double board certified in Reproductive Endocrinology and Obstetrics and Gynecology for People.

While giving in to cravings isn’t the end of the world, a little moderation can help you avoid feeling sluggish later.

“Everybody always thinks that they're gaining weight overnight and that I just have to tell you its physiologically impossible. 

It takes 3500 calories to put on a pound. So unless you're literally eating 10000 calories in one sitting you're not actually gaining 2 or 3 pounds in one day”, continues Dr. Mehr.

Reduced Physical Activity

Let’s be real—when cramps hit, working out is the last thing you want to do. It’s so much easier to curl up on the couch and binge your favorite show. 

But skipping workouts can make you feel even more weighed down, especially if you’ve been giving in to those cravings.

Magnesium and Hydration Imbalances

Magnesium levels in your body naturally decrease as your body prepares for the period. Since magnesium helps regulate hydration and cravings, low levels can make your body feel dehydrated, even if you’re drinking water. 

Dehydration can sometimes mimic hunger, causing you to eat more than necessary. Plus, low magnesium can trigger a sweet tooth, so if you’ve been eyeing that chocolate bar, now you know why.

Tips to Manage Period-Related Weight Gain

Feeling like your body has its own agenda during your period? Don’t worry—there are simple ways to manage that temporary weight gain and feel more comfortable. Here are some practical tips to help:

• Stay Hydrated: It might sound paradoxical, but drinking plenty of water can actually reduce water retention. When your body is well-hydrated, it’s less likely to hold onto extra fluids.
• Eat Fiber-Rich Foods: Foods like fruits, vegetables, and whole grains can help with digestion and ease bloating or constipation. Bonus: They keep you feeling fuller for longer!
• Choose Complex Carbs: Craving something sweet? Go for complex carbs like sweet potatoes, oats, or quinoa. They help stabilize blood sugar levels and keep those cravings in check.
• Exercise Regularly: Even if you’re not up for a full workout, light activity like walking, yoga, or stretching can boost circulation, flash out the salt from your body, ease bloating, and lift your mood.
• Include Magnesium-Rich Foods: Add foods like nuts, spinach, and dark chocolate to your meals. 

Small changes like these can make a big difference in how you feel during your cycle. Try a few and see what works best for you!