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How Can Weight Affect Your Periods?

Maitri Woman

Team Maitri

Dec 23, 2021

Ever noticed that a sudden increase or decrease in your weight often correlates with an irregularity of your menstrual cycles? Research indicates that both, weight gain or weight loss over a short span of time, can affect your menstrual cycles and lead to irregular periods.

A study on 786 Australian women revealed that being obese is associated with irregular periods regardless of whether it is overall obesity or only central obesity (increased fat deposition around waist/abdomen & upper body).

On the other hand, a rapid decrease in weight, with approximately 20% weight loss over a short span of time also leads to irregular periods.

Oh well, this seems like a catch-22 situation ! You can’t be having too much weight, & conversely even weight loss can lead to irregular menstrual cycles ! What is a girl supposed to do?

Don’t worry, we are here to make sense of all the confusing scientific jargon for you and to help you understand the finer points of the relationship between your weight and your periods.

So, first of all, you need to understand that your weight is not an absolute measure of your body mass or health status. The status also depends upon how that weight is distributed along your height. So, a girl with seemingly high body weight, might be tall & with adequate weight distribution along her height and may actually be quite fit; whereas someone who has apparently average weight might be actually quite short or be having uneven weight distribution over the body & have excess fat deposition around the waist /abdomen and may really be technically at risk for obesity related disorders. This risk & level of fitness is best gauged by calculating the Body Mass Index ( BMI) and the Waist to Hip ratio.

What is BMI?

Body Mass Index (BMI) is a measure of body size which takes into consideration two factors- body weight and height.

BMI helps to decide whether you are underweight, healthy, overweight or obese. It can help you understand the effects of your weight on your period.

So how do you calculate BMI?

Calculating your BMI is quite easy, all you need is a weighing machine and a scale or measuring instrument to check your height.

Step 1: Note your weight in kilograms (kg) and height in metres (m).

Step 2: Now, divide your weight in kg by height in metres squared (m2).

BMI = kg/m2

Use this formula and calculate your BMI.

Step 3: Once you get the number,you can check which category you belong to according to your BMI.

BMI table:




Below 18.5

Normal BMI

18.5-24.9 (for Asian women- 18.5- 22.9)


25-25.9 (Asian women- 23-24.9)


>30 ( Asian women- >25)

How do you calculate the Waist to Hip ratio?

The Waist to Hip ratio ( WHR) compares the size of your waist in relation to the hip size. It gives an indication about how the fat is distributed around your body. Women who have more fat deposition around the abdomen are at a higher risk of developing Insulin resistance, diabetes, heart disease, high blood pressure & PCOS.

So to compare the waist size & the hip size, you need to measure the waist circumference by wrapping a measuring tape around the narrowest part of your waist. The hip size is measured by wrapping the tape around the widest part of the hips. To obtain the ratio, simply divide the waist circumference by the hip circumference with the help of a calculator.

A waist to Hip ratio of >0.85 indicates increased risk of Diabetes, Heart disease, PCOS, Metabolic complications. For more details on WHR, do watch the Maitri video & read the article.

How does being overweight affect your periods?

Now that we understand the basic interpretations of body weight, height & fat distribution, we can discuss the impact of body weight & fat content on the overall functioning and menstrual cycles.

Studies have shown that obese women are more likely to have menstrual irregularities. This is attributed to various complicated factors, but to state it in simple language we can say that the fat cells in the body, especially those around the waist & abdomen, produce hormones that affect the reproductive cycle & function of the ovaries.

This is so because, the fat cells, apart from being a storehouse of excess calories /energy, also convert the androgens circulating in the blood stream to estrogens and thus contribute to the overall levels of estrogens in the body. Besides, in obese women, the levels of SHBG ( Sex Hormone Binding Globulin ) are lower, consequently, a large part of the excess estrogen produced by the fat cells remains unbound & is free to circulate in the body. Consequently, the ovarian function & ovulation is also disrupted. Additionally, when the ovulation is not happening regularly, the uterine lining ( Endometrium ), continues to grow & becomes thicker to a point where it becomes unsustainable & may start to shed irregularly, thus leading to irregular periods.

A recent research also suggests that obesity may be linked to heavier periods. This is so because obese women may have increased inflammation in the lining of the uterus and the repair of this lining may be delayed in obese women during periods. As a result, the blood loss is more and they have heavier periods compared to women with normal body weight. This is an interesting finding but requires further research to be accepted unconditionally.

How does weight loss affect your periods?

It is well known that women with normal BMI and normal WHR are more likely to have regular ovulation, regular periods & a better health overall.

Studies claim that weight loss in obese women is associated with decrease in the production of excess estrogens, decreased cortisol levels and an improvement in menstrual & reproductive functions.

So the impact of excess body weight & BMI on the periods may inspire you to lose that excess weight & get rid of your period problems, right? But hold your horses, this is not really that simple.

Women who are extremely underweight or have eating disorders like anorexia nervosa, or those who follow extremely intense exercise regimens, may actually have too little estrogen in the body to maintain the reproductive and menstrual functions. As a result, even underweight women may have irregular periods.

Many studies also claim that a rapid weight loss may also lead to irregular periods. So women who lose 20% or more of their weight over a short span of time have increased stress levels, increased cortisol, disruption of the Hypothalamus-Pituitary-Ovarian axis leading to irregular periods. So what is the solution? Well, as always, it is better to choose the middle path. Lose the excess weight but do it gradually. Aim at reducing 5% of your body weight initially and then work towards maintaining that weight loss. Lose the excess weight & try to arrive at your normal BMI in a gradual, stepwise pattern.

Do you really gain weight few days prior to your periods?

The menstrual cycle does not actually affect weight gain or loss per se. Your period may affect your weight in many ways. Basically, what happens is, many women experience food cravings in the days just prior to their periods (the pre-menstrual phase). When this happens, they tend to eat more of sweet or salty foods than normal. These extra calories consumed are the real reason for the weight gain. On the other hand, salty foods retain water in the body, which increases the body weight. This extra weight is not fat, it is due to the excess water retention in the body.

So, if you happen to check your weight a few days prior to your period or on your periods and you find the scale moving on the side of weight spectrum, don’t just blame your periods for this, watch your diet and control the weight gain.

What can you do about it?

So looking at all the various aspects of the effects of weight on your menstrual cycles may make you feel quite overwhelmed & powerless at first instance. But take heart, it is not impossible to gain back the control of your life if you decide to do so. The steps to achieve an optimum weight & regular cycles are simple and can be listed as below:

  • Managing to stay within the normal BMI range: So we have seen that BMI plays a significant role to determine whether or not your periods are normal. If you are overweight and suffering from irregular periods, it is better to take steps to reduce your weight gradually. If you are underweight, you must focus on gaining healthy weight. It is very important to note that both gaining and reducing weight has to be a gradual process & should not be too rapid. Don’t go for crash diet plans to lose weight or eat too much of high calorie food to gain weight. The losing and gaining weight process need to happen gradually, otherwise, the problem can worsen.
  • Eating right: It is very important to consume healthy food if you are aiming at bringing your BMI to normal levels. Stay away from packaged foods, foods that come with the ‘fat-free’, ‘protein rich’, etc. labels as they are highly processed. Try and eat foods in their natural form without making too many alterations. Eating too less, overeating or depriving yourself of essential nutrients in the name of weight loss is not sustainable. Your body needs a blend of all nutrients in the right amount to carry out its functions properly.
  • Exercise: Moderate exercise for at least 150 minutes a week, should be a part of your schedule. Do simple forms of exercise like walking, yoga, jogging, swimming, pilates, aerobics, sports or any form of physical activity that makes you sweat a little. If you are someone who is into hard core exercise regimes and you feel your periods are irregular, you may have to slow down.
  • Stress management: Stress plays an important role in weight gain or weight loss and as such is an important contributory factor to menstrual irregularities & period problems. Take steps to reduce your stress levels by better time planning, doing meditation, any fun activity that you enjoy and getting adequate sleep on a priority basis. Even physical exercise is a stress-buster as it releases endorphins or ‘happy hormones’ that are mood elevators. Studies show that reducing stress levels have a positive impact on the menstrual cycles and overall reproductive function.
  • Guidance: Before starting any course of dietary changes or exercises, it is very important that you speak with a healthcare provider who will be in a better position to guide you to suit your body’s needs. It is also important because your doctor will be the best person to determine whether your irregular periods are only because of your weight issues or if there is an underlying medical condition that needs to be treated. Do not depend upon the advice given by random people as they may not know the real cause of your problems.

As complicated as it may seem, managing your weight and its effect on your periods is an achievable target if you follow the right diet & physical exercise regimes. Do not hesitate to seek guidance & ask for help when required and motivate yourself to take that first step towards gaining control of your body & your life. It is doable once you start doing the work.

Maitri Woman

Team Maitri

Dec 23, 2021

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