Weight Gain During Periods: What's Happening

• Researched and written by: Dr Akshara CH, MBBS
• Medical inputs by: Dr Poonguzhali Liston, MBBS, MS OBG, FMAS, DRM, FRM, CIMP
• Medically reviewed by: Dr Yash Bahuguna, MBBS, MS, DNB, ISGE Certified Practitioner for PCOS

TL;DR

• Short-term weight changes happen across the menstrual cycle.[1,2,3]

• These changes reflect water retention, bloating, rather than fat gain.[2,3,4,5,6]

• Body weight usually settles back to baseline during or after menstruation.[3,4,5]

• The amount of change varies widely between individuals and from one cycle to another, depending on fluid handling, digestion, and symptom sensitivity.[1,2]

• For most people, these fluctuations are small, temporary, and considered a normal part of menstrual physiology rather than a health concern.[1,11]
  
  

What Does Weight Gain During Periods Mean?

When people talk about gaining weight around their period, they are usually describing short-term changes that occur during the days before your period which shows up as a higher number on the scale.

Along with this, you may notice physical changes such as:

• Bloating or abdominal fullness

• A heavier or puffier feeling in the body

• Visible swelling, especially around the abdomen, hips, breasts and also around ankles and lower limbs.
  

Research consistently describes bloating and fluid retention as common physical symptoms of the second half of your menstrual cycle, and of premenstrual syndrome (PMS).[1,2,3] These changes often occur alongside other physical and emotional symptoms, such as breast tenderness, digestive discomfort, fatigue, or mood changes, rather than on their own.[2]

What research tells us: While water retention and bloating are common, there is no single, generalisable percentage for how many women experience these specific symptoms across the menstrual cycle. Most evidence relies on symptom reporting, which is why individual tracking over several cycles can be more informative and helpful.[1]

Why Does Period Weight Gain Happen?

This happens because normal processes in the body change across your menstrual cycle. Although we do not know the exact biological causes that lead to weight gain, the following are some explanations why weight can fluctuate around a period.

Temporary fluid changes during the menstrual cycle

Across the menstrual cycle, your body’s fluid balance naturally shifts. Studies that tracked daily changes show that total body water tends to increase in the luteal phase due to progesterone dominant effects and then fall again once menstruation begins.[3,4] This helps explain why some people notice swelling, bloating, or a puffy feeling in the days before their period, which usually eases after bleeding starts.[2]

These fluid changes do not happen evenly throughout the body. Some of the extra water moves from the bloodstream into surrounding tissues rather than staying in circulation. This is why swelling may be more noticeable in areas such as the abdomen, hips, breasts, or limbs.[2,3]

This temporary increase in water retention can show up as a small increase on the scale or a feeling of heaviness or tightness. As hormone levels change and menstruation begins, fluid balance shifts again, and this extra water is usually released, bringing weight and swelling back toward your usual baseline.[3,4]

Slower gut movement 

Progesterone, a hormone which rises after ovulation is known to have a relaxing effect on smooth muscle, which may slow gut movement in some individuals⁷ This means digestion may slow slightly in the days before a period. When food moves more slowly through your gut, that may lead to a feeling of fullness or heaviness. This can make the abdomen look or feel more bloated and can also push the number on the scale upward.[5,6]

Short-term appetite and intake changes

Some studies have found that appetite increases slightly in the days before a period for some people.[8] This often shows up as eating a bit more overall, or craving more carbohydrate-rich foods.

When you eat more carbohydrates, your body stores the excess carbohydrates as glycogen. This holds on to water, which can temporarily cause an increase in weight.[9] This shows up on the scale as a short-term change, even though it is not fat gain.

Other Factors That Cause You To Gain Weight During Your Period

Not everyone experiences period-related weight changes in the same way. The intensity you feel can also vary from one cycle to another. Research points to a few key reasons:

• Severe PMS symptoms: Some women naturally experience stronger symptoms of PMS, which can make bloating and water retention more noticeable.[1,2]

• Salt intake: Eating more salty foods can make your body to hold on to extra water, making short-term weight changes more obvious.[10]

• Stress and sleep: Stress and poor sleep can worsen period bloating and make it harder to maintain routines like balanced eating and regular movement that help manage premenstrual weight fluctuations.[11]
  

• Hormonal contraception or health conditions: Hormonal birth control and certain endocrine or gastrointestinal conditions can cause hormonal changes influencing how fluid retention, bloating, and other symptoms show up across the cycle.[12,13]
  

How Weight Shifts Before, During, and After Your Period

We saw why these short-term weight changes happen and what can influence them. Looking at how weight typically shifts before, during, and after your period helps put those explanations into a clear, day-to-day pattern across the cycle.

Premenstrual phase (about one week before your period)

In the week before your period, progesterone is higher. This can cause your body to hold on to more fluid and shift water into tissues. Digestion may slow slightly, so food stays in the gut longer. Some people also notice a bigger appetite or more cravings. Together, this can show up as bloating, puffiness, or a small temporary increase in scale weight.[3,4,5,6,7,8,9]

Menstruation (during your period)

Once your period starts, estrogen and progesterone drop. As this happens, your body begins to release the extra fluid it was holding on to. Digestion slowly picks back up. For many people, weight starts to come down during this time, although bloating may linger for a day or two.[2,3,4,7]

Early follicular phase (after your period)

After your period ends, hormones stay relatively stable and progesterone remains low. Fluid balance returns to normal, digestion feels easier, and abdominal fullness settles. Body weight typically returns to its usual baseline until the next cycle.[3,4,5]

Why Some People Notice Period Weight Gain More Than Others

PMS can feel very different from one woman to another.[1,2] Some may notice clear physical changes with almost every cycle, while others experience little or nothing at all.

A big part of this comes down to individual differences, such as:

• How much fluid your body tends to hold on to before a period

• How quickly or slowly your digestion usually works

• How strongly you notice physical sensations like bloating or heaviness
  

Together, these differences help explain why short-term weight changes feel very noticeable and uncomfortable for some people, but barely register for others, even when hormone patterns are similar.[2,5,6,7]

Berry’s Tips: How to Manage Period-Related Weight Gain

Understanding what’s normal at different points in your menstrual cycle and using simple comfort and symptom relief strategies can make it easier to manage changes and help you feel better. 

Drink enough water across the day

Drinking plenty of water across the day can be helpful. Aim for at least around six to eight glasses of water daily, or about 1.5 to 2 litres for most adults. You may need more than this if you are physically active, spend time in hot weather, or are unwell. Replace sugary drinks for diet, sugar-free or no added sugar drinks. Staying well hydrated supports digestion and normal fluid balance, which may help reduce the feeling of bloating that some women notice before a period.[10]

Engage in gentle movement

Regular physical activity may help reduce the temporary weight changes and a heavy feeling some women experience before a period. A 30 minute moderate movement on most days, such as brisk walking, cycling, or swimming or even a short walk of 10 mins after meals can be comforting for overall wellbeing, not just for weight loss.[14]

Choose foods that feel gentler on your digestion

Management includes reducing the amount of foods that can contribute to temporary weight gain before a period. This often includes food that increase water retention or digestive discomfort:[5]

• Limiting very large or heavy meals

• Cutting back on excess caffeine and alcohol

• Reducing highly salty or sweet foods
  

Eating a lot of salty foods in the premenstrual phase can cause the body to retain more water. Moderating salt intake during this time may help limit water retention and bloating.[10]

Taken together, these approaches are meant to support comfort and confidence through the premenstrual phase.

When to See a Doctor

Although short-term bloating and weight changes are common, feeling any of the following may require a consultation with your healthcare provider.

• Your weight changes or bloating do not settle after your period. Feeling heavier, puffy, or bloated most of the month, rather than mainly in the days before your period, may need evaluation.[11,12]
  

• You have other symptoms along with bloating and weight gain. This can include ongoing pelvic pain, unusual bleeding, digestive symptoms that persist, marked fatigue, or frequent dizziness.[11,12,13]

• Your daily life is affected. Symptoms that interfere with work, sleep, exercise, or your usual routines are a reason to seek advice.[11]
  

These patterns may point to something beyond typical premenstrual changes and are worth discussing with a healthcare professional.

The Bottom Line

Small weight changes around your period are a normal part of the menstrual cycle. They reflect temporary shifts in fluid balance and digestion, not fat gain. For most people, these changes ease on their own as the cycle moves on, especially with simple supportive habits. Keeping this in mind can take pressure off the scale and help you focus on overall patterns and how your body feels over time, while also recognising when it’s important to seek care if symptoms feel unusual or concerning.

FAQs on Period Weight Gain

Is period weight gain real or just bloating?

It’s real as a short-term change, but it reflects water retention, bloating, and digestion changes, not fat gain.

How much weight do people usually gain before their period?

While the number is not fixed, most people notice a small change, though this varies widely between individuals and cycles.

Does period weight gain mean hormones are out of balance?

No, these short-term changes are usually a normal response to hormonal shifts across the menstrual cycle.

Can you prevent weight gain during period?

It can’t be fully prevented, but hydration, gentle movement, and moderating salty foods may help reduce discomfort.

When should I worry about weight changes around my period?

If changes are severe, long-lasting, disrupt daily life, or occur with other concerning symptoms, medical review is advised.

References

1. American College of Obstetricians and Gynecologists. Premenstrual syndrome (PMS). Accessed December 25, 2025.

2. Tacani PM, Ribeiro DO, Barros Guedes MJ, et al. Characterization of symptoms and edema distribution in premenstrual syndrome. Clinics (Sao Paulo). 2015 Sep;70(9):589–595.

3. White CP, Hitchcock CL, Vigna YM, Prior JC. Fluid retention over the menstrual cycle:. Clin Sci (Lond). 2011 Apr;120(9):365–372.

4. Kanellakis S, et al. Changes in body weight and body composition across the menstrual cycle. Nutrients. 2023 Jul 5;15(13):2961.

5. Heitkemper MM, Cain KC, Jarrett ME, et al. Gastrointestinal symptoms across the menstrual cycle. Gastroenterology. 2003 Apr;124(4):930–938.

6. Pati GK, Kar C, Narayan J, Uthansingh K, Behera M, Sahu MK, Mishra D, Singh A. Irritable bowel syndrome and the menstrual cycle. Cureus. 2021 Jan 14;13(1):e12692.

7. Reed BG, Carr BR. The normal menstrual cycle and the control of ovulation. Endotext. National Institutes of Health. Accessed December 25, 2025.

8. Dye L, Blundell JE. Menstrual cycle and appetite control. Hum Reprod. 1997 Apr;12(6):1142–1148.

9. Kreitzman SN, et al. Glycogen storage and water retention. Am J Clin Nutr. 1992 Jul;56(1 Suppl)

10. National Health Service. Water, drinks and nutrition. Accessed December 25, 2025.

11. Royal College of Obstetricians and Gynaecologists. Management of premenstrual syndrome. Accessed December 25, 2025.

12. National Institutes of Health. MedlinePlus. Premenstrual syndrome overview. Accessed December 25, 2025.

13. Schiller CE, Johnson SL, Abate AC, et al. Reproductive hormone fluctuations and mood. Curr Psychiatry Rep. 2016 Oct;18(10):93.

14. Daley A. Exercise and premenstrual symptomatology. J Womens Health (Larchmt). 2014 Jun;23(6):540–548.