Nearly everyone has probably noticed their body weight go up and down during different chapters in life and during certain times of year (like in the midst of holiday feasting). What we sometimes don’t realize, though, is that these changes can happen on even a daily or a weekly basis. Of the many factors that cause body weight fluctuations, one that exclusively affects women is the menstrual cycle. And one of the possible side effects of this complex biological and hormonal process is temporary weight gain. 

What Happens During the Menstrual Cycle?  

The menstrual cycle (or period) is a normal part of the reproductive process and an important component of preparing the body for a potential pregnancy. The start of a period is marked by the shedding of the lining of the uterus and the passing of this blood and tissue out of the vagina; this typically happens over 3-5 days. This added layer of spongy tissue in the uterine wall is ideal for holding and supporting a fertilized egg, and it is during the second phase of the menstrual cycle that it begins to form. 

The lining of the uterus is prepared just in time for the next phase: ovulation. This is when an egg produced in an ovary travels down one of the fallopian tubes and is available to be fertilized by sperm. If fertilization occurs during the relatively short window of ovulation, the fertilized egg will become attached to the uterine wall and begin to develop. If fertilization doesn’t occur, the egg eventually gets absorbed by the body. At that point the thicker lining begins to separate and then is shed and the whole cycle begins again. 

Menstruation begins for most women around the age of 12, though it can happen earlier or later. It continues every month (usually around 28 days) until menopause, a phase of life in the early 50s where periods stop and a woman can no longer become pregnant. The whole cycle is governed by sex hormones like estrogen and progesterone that are made and released by the pituitary gland and the ovaries. 

Symptoms Related to Menstruation

Changes to hormone levels during the menstrual cycle are also thought to be linked to the symptoms associated with having a period. Some of these symptoms may occur throughout the cycle, but some only happen during the time of the month when the period starts and cease once bleeding begins; this collection of symptoms is known as premenstrual syndrome (PMS). Below are some common symptoms related to menstruation: 

• trouble sleeping
• anxiety
• irritability and mood swings
• body aches or headaches 
• tenderness in the breasts
• diarrhea or constipation 
• bloating 
• acne
• food cravings

How Does a Period Lead to Weight Gain?  

Doctors have long observed a tendency for women to gain a small amount of weight in the week or two before their period. A recent study found that 65% of women had swelling as one of the symptoms of PMS, and they noted that swelling is a significant factor in real or perceived weight gain. There is evidence, however, of a number of different reasons behind why weight gain can accompany a period: 

• Fluid retention: Two hormones involved in menstruation—estrogen and progesterone—are present in higher amounts during the couple weeks before a period. In addition to their role in the reproductive process, they can indirectly lead to water retention by drawing more salt and water from blood vessels to surrounding tissues. This leads to water weight gain as well as swelling and other symptoms.
• Increased appetite: Higher progesterone levels have also been shown to stimulate appetite during the luteal phase of the menstrual cycle. Higher overall appetite and sudden food cravings can easily lead to overeating. Moreover, for many people, the cravings tend to be for salty or sweet foods that can add to fluid retention and swelling. 
• Constipation: Constipation is another possible side effect of higher levels of progesterone. This hormone also acts as a muscle relaxant, especially for the smooth muscle that covers the gastrointestinal tract. This relaxing effect can then slow down bowel motility and lead to constipation, bloating, and weight gain. 
• Reduced physical activity: Some of the symptoms of premenstrual syndrome can be difficult to manage and may lead to changes in physical activity level, either because of a lack of motivation or physical discomfort. Less exercise or being very sedentary can lead to weight gain in part by contributing to water retention and bloating. 

Avoiding Period Weight Gain          

The hormonal changes associated with the menstrual cycle can have a variety of different symptoms, and different women can have different combinations of symptoms. Even when weight gain is a symptom, though, it is usually only temporary and diminishes once bleeding begins. Still, there are some ways to avoid some of the added weight—particularly the weight related to fluid retention: 

• Drink water: Even though it may seem counterintuitive, drinking plenty of water can flush out some of the salts that are also retained during PMS. 
• Reduce salt: Since progesterone causes the body to retain salt, it’s important to reduce the dietary intake of salt. This can be done by avoiding salty foods and not adding salt during meals or cooking.  
• Move more: The symptoms of PMS can sometimes conspire to make exercise seem daunting, but it’s actually very beneficial to exercise or at least get up and move around more frequently. In addition to limiting fluid retention and the water loss from sweating, exercise also increases endorphin levels and encourages feelings of wellness. 
• Diet changes: Beyond reducing salt intake, there are also some foods that are helpful to emphasize: whole grains, yogurt, leafy green vegetables, lean meats, fish, and fruits that are high in potassium. It’s also a good idea to limit beverages with alcohol or caffeine in them (or avoid them altogether). 
• Diuretics: A diuretic is a substance that increases the amount of water that is excreted through urination. There are many foods and supplements that have this effect and counteract the extra water weight. 

Alternative Weight Loss Solutions

The kind of weight gain that’s associated with the menstrual cycle can usually be explained by changes to the body’s fluid balance. This kind of gain is also mostly limited to a few extra pounds. However, a trend of overeating and exercising less can eventually lead to weight gain from increased fat deposits. This type of weight gain might be accentuated by period weight gain, but it has a different cause and a different solution. 

If you’ve ever tried to lose weight, though, you know that it isn’t easy. In fact, most Americans who attempt to lose weight just through diet and exercise don’t have long term, lasting success. At True You Weight Loss, we are dedicated to helping people on their journey by providing alternative weight loss solutions that are designed to help you lose weight and keep it off. If you would like to learn more about our services and what is involved, please contact us today to request a consultation!