Metabolic Health 20 MIN READ

Ultimate guide on the Menstrual cycle and metabolic Health

The first day of your period marks the start of your menstrual cycle or menstruation and happens almost monthly when your next period starts. Throughout this process, your body produces different kinds and amounts of chemicals called hormones to prepare for pregnancy.

Written by Team Ultrahuman

Nov 10, 2021
menstural cycle health

Menstrual Cycle

The first day of your period marks the start of your menstrual cycle or menstruation and happens almost monthly when your next period starts. Throughout this process, your body produces different kinds and amounts of chemicals called hormones to prepare for pregnancy.

These fluctuating hormone levels can cause menstrual symptoms or what’s commonly known as PMS. The menstrual cycle changes with age.

A normal cycle can last anywhere from 24-38 days. When you’re menstruating, your body sheds the monthly build-up of the uterus lining (womb).

Menstrual blood and tissue goes from your uterus through the cervix and passes out of your body through the vagina. During the monthly menstrual cycle, the uterus lining thickens to prepare for pregnancy.

If you do not get pregnant, the body’s oestrogen (the primary female sex hormone) and progesterone (the other female sex hormone released from the ovaries, which stimulates the uterus to prepare for pregnancy) levels begin falling. Very low levels of these hormones indicate to your body to begin menstruation.

What Are The Four Stages of the Menstrual Cycle Phases?

1.Menstrual Phase

The first phase is the menstrual phase, which lasts from days 1 to 5 of your cycle. During this phase, the uterus sheds its inner lining through the vagina in the form of fluid & mucuous.

Women generally experience cramps due to the contraction of the uterine wall during this phase. Even though it seems like a lot of blood is lost, the actual measure of blood loss in a menstrual cycle is typically 35 ml.

2.Follicular Phase

The follicular phase starts simultaneously with the menstrual stage but ends on the 13th day. During this phase, the brain releases hormones present in the blood to the ovaries which in turn increases the production of follicles.

Out of the 15 to 20 eggs that are generated in the ovaries, only one matures and continues producing the estrogen hormone. Around the period of ovulation, the testosterone hormone is released as well which increases a woman’s libido.

3.Ovulation Phase

The pituitary gland secretes a hormone that causes the ovary to release the mature egg cell. The released egg cell is taken into the fallopian tube by the cilia of the fimbriae. Fimbriae are finger-like projections located at the end of the fallopian tube close to the ovaries.

Generally, this phase happens on the 14th day but can differ from woman to woman. Sometimes, women may feel a slight cramp in the lower abdomen as the egg is released.

The mature egg will stay in the fallopian tube for an entire day. If during this time, sexual intercourse happens, the sperm cells make their way to the mature egg.

4.Luteal Phase

This phase starts on the 15th day and lasts until the 28th day. If the egg is fertilised, progesterone is still produced in order to thicken the uterine lining for implantation to happen.

After 14 days, the HCG hormone ( which is produced in the placenta and indicates pregnancy) is produced. However, if fertilization doesn’t occur, the progesterone slowly reduces and the body prepares for menstrual periods.

What is Metabolism?

Metabolism is a series of chemical processes in each cell transforming the calories we eat into fuel to keep us alive. These processes sustain life, and everyday functioning and include breaking down food and drink for energy and building or repairing our bodies.

Metabolic health is described as having ideal levels of blood sugar, triglycerides, high-density lipoprotein (HDL) cholesterol, blood pressure and waist circumference, without the use of medications.

Menstrual Cycle and BMR and Resting Metabolic Rate

Basal Metabolic Rate (BMR) is defined as the rate at which the body uses energy while at rest to maintain vital functions such as breathing and regulating body temperature.

A research study published in Proceedings of the Nutrition Society says that women have a slightly higher Resting Metabolic Rate (RMR or the rate at which your body burns energy when it is at total rest) in the luteal phase of their menstrual cycle. This is the period between ovulation and when a person starts their next menstrual period.

A counter-thought is that the RMR may increase during ovulation itself. This is around the time your body releases an egg for possible fertilization. According to Melinda Manore, PhD, RD, Emeritus Professor of Nutrition at Oregon State University, “Resting metabolic rate changes over the menstrual cycle and goes up for a few days during ovulation. That said, the body adjusts to these small changes in RMR and one’s weight typically doesn’t change during the cycle, except for the water retention that may occur.”

However, Manore says the changes are so insignificant that your caloric requirement doesn’t necessarily increase.

According to a study published in The American Journal of Clinical Nutrition, BMR was measured in six healthy young women who were participating in a study of protein requirements.

The women were confined to a metabolic unit for 92 days during which they consumed a pre-defined formula diet. The BMR of the women was 20.7 +/- 2.6 kcal/kg body weight/day and the caloric requirement for maintenance of weight was 38.7 kcal/kg body weight/day.

BMR varied significantly with the menstrual cycle, decreased at menstruation and fell to its lowest point approximately one week before ovulation, subsequently rising until the beginning of the next menstrual period.

RMR was 0.99 +/- 0.16 kcal/kg/h. The energy expenditure while sitting was 1.06 times the RMR while walking it was 2.81 times the RMR and while performing treadmill exercise it was 3.47 times the RMR.

Menstrual Cycle Hormones and Metabolism

In women, there’s a physiological explanation behind fluctuating hormones. While men’s hormone levels do change over a lifetime, in the day-to-day, they tend to remain quite stable.

However, women experience fluctuating levels of sex hormones daily. Due to the fluctuation of hormones, scientists know different phases of the menstrual cycle and how they can affect metabolism and recovery from exercise, particularly for women who take part in endurance activities.

During the follicular phase between days 1-14, the level of oestrogen progressively increases and that of progesterone stays stable. At this time, women are physiologically much more similar to men in their metabolism and recovery.

Training will feel easier and you will recover more quickly than during the luteal phase. Around day 12, the levels of oestrogen and another type of hormone, the luteinizing hormone, surge, triggering ovulation. You’re likely to experience an increase in energy and strength at this time.

The luteal phase represents the second half of a woman’s cycle period. During this phase, the progesterone levels peak, resulting in an increase in resting heart rate and a decrease in capacity for aerobics and the ability to withstand heat.

The body burns more fat during the luteal phase, as the peak in oestrogen and progesterone suppresses gluconeogenesis which is the process of the making of sugar from protein and fat.

BMR in menstruating individuals actually starts decreasing during the bleeding portion of the cycle. It hits its lowest point around one week after menstruation begins and then rises again until the next period starts.

There is good evidence that progestogens, such as progesterone, can stimulate appetite. Levels of this sex hormone reach their peak about one week before menstruation begins, which can help explain those pre-period munchies.

In a similar way, while BMR decreases during menstruation, it rises to its highest just before it. The variations in BMR during a menstrual cycle have been estimated by researchers as roughly 8 percent, or 164 calories, approximately the amount of energy found in 1.5 navel oranges, or ¾ of a Kit-Kat bar. It’s not a huge quantity, but it is big enough to impact your hunger leading up to and at the beginning of your period.

A 2016 study suggests that changes in levels of oestrogen and progesterone cause cravings for high-carb and sweet foods before your period.

Your hormones may not be the only driving force behind your desire to eat all the goodies in your pantry before Aunt Flo comes to town, though. Eating all the foods can also help you combat all the intense mood swings that accompany the premenstrual stage of your cycle.

Your body releases serotonin (a neurotransmitter that regulates mood, cognition, learning, memory and increases feelings of well-being and happiness) when you eat starchy foods and sweets. A boost in good feelings is always nice, but even more so when your all-over-the-place hormones have you feeling all PMS-y.

Menstrual Cycle Rhythmicity

The monthly menstrual cycle is one of the many physiological rhythms important for life. One’s heartbeat and the daily sleep–wake cycle represent obvious rhythms. Less obvious are the physiological processes inside the body, such as the rhythmicity of the sex hormones that drive the menstrual cycle and others that regulate growth and metabolism.

Perturbations of the body’s rhythmic processes are associated with disorders such as disturbed circadian rhythmicity with the premenstrual dysphoric disorder (PMDD) or abnormal expression of the circadian clock gene.

The menstrual cycle is an important rhythm of life governed by levels of progesterone, oestradiol, follicular stimulating hormone (FSH) and luteinizing hormone (LH) that interact with each other.

To study metabolic changes, biofluids were collected at four-time points in the menstrual cycle from 34 healthy, premenopausal women. Urinary luteinizing hormone, serum hormones and self-reported menstrual cycle timing were used for a 5-phase cycle classification.

In the luteal phase, possibly indicative of an anabolic state during the progesterone peak and recovery during menstruation and the follicular phase, the reduced metabolite levels observed may represent a period of vulnerability to health issues which are hormone related such as PMDD and premenstrual syndrome (PMS), in the setting of a healthy, rhythmic state.

These results provide a foundation for further research on cyclic differences in nutrient-related metabolites and may form the basis of novel nutrition strategies for women.

The second half of the cycle consists of the luteal (during which time the oestrogen level rises with a progesterone peak) and the premenstrual phases during which time the oestrogen and progesterone levels fall.

However, it is during this time that women experience a worsening of chronic diseases such as diabetes and inflammatory bowel disease, bloating, poor sleep quality and premenstrual syndrome (PMS) or PMDD.

These biochemical changes suggest that the utilization of nutrients is affected by changing sex hormones between phases. The luteal phase of the menstrual cycle may be considered a normally stressed physiology which amplifies the differential responses between individuals to environmental stressors such as diet intake. These differential responses might predict future chronic health issues.

Does Menstrual Cycle Affect Blood Sugar levels?

Oestrogen and progesterone control both your menstrual cycle and your blood glucose, so when you experience fluctuations in your blood-sugar levels it can often be attributed to a certain point in your monthly cycle. When oestrogen and progesterone are at their highest levels, they affect insulin, which is also a hormone. This can cause your blood glucose to rise if your body becomes more resistant to the effects of insulin.

According to this study, results reveal that although BMI (a measure of body fat based on height and weight) did not differ significantly between menstrual and luteal phases, there was a positive correlation between changed BMI value and changed blood glucose level measured during the menstrual and luteal phases.

Multivariate analysis revealed that the blood glucose level increased with the increase in the BMI level between two phases of the menstrual cycle.

There are 4 primary hormones affecting the menstrual cycle: oestrogen, progesterone, LH and FSH. Each hormone affects blood sensitivity and sugar to insulin differently.

Let’s look at the entire period cycle, starting with the first day of the period.

Between days 1 to 10, you may experience higher blood sugars and insulin resistance on the first day, but the insulin sensitivity should revert to normal for the rest of your period, and a few days after it ends.

Between days 11 to14, you’re ovulating, so you may experience higher (and somewhat erratic) blood-sugar levels and insulin resistance once again. When your body is preparing to release an egg, the levels of LH, FSH and oestrogen all rise, which can cause a spike in your blood sugar lasting 2 to 3 days at the most.

Between Days 15 to 20, your blood-sugar level drops closer to its typical level for a few days. And during days 21 to 28, the mid-luteal phase, you’re more likely to experience significant insulin resistance and higher blood-sugar levels before you start your next period.

Here are a few tips to minimize food cravings:

  1. Limiting your intake of chocolate, caffeine and alcohol as they can cause mood fluctuations and increase the likelihood of you reaching for the high-carb, high-sugar treats,
  2. Have regular mealtimes and avoid snacking throughout the day,
  3. If you do need a snack, stick to low-fat, low-carb treats that are less likely to spike your blood glucose levels,
  4. Regularly exercise throughout the month to decrease your blood glucose levels and manage your mood.

How Does Menstrual Cycle Affect Metabolism?

Metabolic syndrome is a cluster of conditions that occur together, increasing your risk of heart disease, stroke and type 2 diabetes. These conditions include increased blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol or triglyceride levels.

Many issues affecting women’s health can have roots in poor blood-sugar control and insulin resistance.

These infertility, weight management menstrual dysfunction, include polycystic ovarian syndrome (PCOS), skin health and menopausal symptoms. Menopause occurs after a certain age(50+) it’s the end of a woman’s menstrual cycles.

PCOS is one of the primary causes of infertility, and women with PCOS are more likely to be insulin-resistant and be in danger of developing diabetes. PCOS is a condition of hormonal imbalance and so symptoms vary widely.

They can include obesity, infertility, increased levels of male hormones, irregular menstrual cycles, thinning scalp hair, excess body hair, acne and several small follicles, or collections of cells with fluid, on the ovaries.

In addition, PCOS has metabolic consequences. Research shows that about 70 percent of women with PCOS experience insulin resistance. The Centers for Disease Control and Prevention reports that more than half the number of women with PCOS develop type 2 diabetes by age 40.

Some research shows that women with PCOS and high levels of androgens have higher blood glucose levels than women with PCOS who have lower androgen levels.

Fluctuations in oestrogen and progesterone hormones during the menstrual cycle impact glucose metabolism and insulin sensitivity. In general, researchers believe oestrogen promotes insulin sensitivity, while progesterone promotes insulin resistance.

Studies show that glucose concentrations can sometimes be higher in the luteal phase compared to the follicular phase, as the higher levels of progesterone decrease insulin sensitivity. This means insulin is not as efficient at clearing glucose from your blood, leading to higher levels.

By age 45, women are more likely to be overweight or obese than men, and insulin resistance (that happens in part by excess blood glucose) plays a significant role in obesity; although hormonal changes may also be a factor. During menopause, for example, women lose oestrogen and the protective effects that come with it. Loss of oestrogen is directly linked to increased visceral fat, higher cholesterol levels and progression of metabolic syndrome.

Obesity Phenotypes and Menstruation

According to research, general obesity reflects the overall body mass, i.e. a large lean (muscle) mass. Central obesity has been proven to be an accurate measure of abdominal fat accumulation and a good predictor of morbidity and mortality, especially better than general obesity. Visceral obesity is a well-known risk factor for many diseases such as metabolic disease, hemodynamic disease, type 2 diabetes and stroke.

According to a study published in BMC Endocrine Disorders, menopause is an independent risk factor for central and visceral obesity but not general obesity.

Women at different ages going through menstruation undergo different physical and psychological changes. Women in the postmenopausal period tend to have a higher risk of disease, co-related to obesity, probably due to a sharp decrease in the levels of sex hormones after menopause. Increased oestrogen levels have been reported to affect weight gain by increasing energy expenditure and by regulating metabolism and the distribution of adipose tissue.

Period (Menstrual Cycle) Inflammation

Inflammation is the process in which the body’s white blood cells and what they make protect you from infection from foreign invaders such as viruses and bacteria.

As your body approaches ovulation and prepares to release an egg, it is readying itself for the possibility that a fertilized egg could be implanted in the uterine lining and begin to grow. This newly fertilized egg would have half your DNA and also be half foreign (with the foreign DNA coming from the sperm). Your immune system relentlessly seeks out and destroys cells in your body that don’t belong there (think bacteria, viruses and even your own seemingly cancerous cells). All these are things that your body wants to desrroy, but right around ovulation time it has to prepare for the possibility that an entire bunch of cells that don’t match your DNA are going to be growing inside you, and that your immune system isn’t supposed to be kilingl them.

As a result, hormonal cues during ovulation dial down your immune system so it is less likely to attack the newly fertilized egg. However, this dialling down of the immune system also makes women more likely to get an infection during and after ovulation. Once you are past that fertile window, the immune system responds strongly as your body switches into menstruation mode.

This switch helps break up and clear out the uterine lining (which could reduce your risk of infection), but it can also exacerbate inflammation and certain immune diseases. The more inflammation you have in your body as your immune system swings into action and your period starts, the worse PMS you’ll probably have.

Research around inflammation and more acute PMS is only a few years old but can potentially have important health implications because inflammation is a significant risk factor for many diseases including heart disease Alzheimer’s and type 2 diabetes.

How to deal with period cramps? or take Care during Periods

There are some simple things you can do to feel better during your period.

Menstrual cramps are totally commonplace and can start a day or two before the period, sometimes even a few days prior.

They are caused by uterine muscle contractions due to the release of a hormone called prostaglandin — which is a totally normal and expected part of the menstrual cycle. While some women experience mild symptoms, others experience nausea, loose stool, headaches and dizziness.

If you’re experiencing severe symptoms, it’s a good idea to consult your doctor as it may be a sign of something more problematic.

If your menstrual symptoms are mild.

Here are home remedies that may help alleviate period cramps and reduce the pain:

  1. Use a heating pad or place a hot-water bottle on your lower abdomen or lower back,
  2. Take a warm bath,
  3. Massage your abdomen,
  4. Consult your doctor about using an over-the-counter pain reliever or muscle relexant or anti-inflammatory drug,
  5. Do easy exercises like yoga, walking or swimming to help increase blood flow.

The period bloat is a common symptom you can experience before and during your period, making you feel like you’ve gained weight or have a tight and swollen abdomen.

Additional self-care during your periods

1.Water is your friend:The more water you drink, the better. There’s no specific recommendation of how much water each unique person should drink but a common guideline is to drink 8–10 8-ounce glasses of water throughout the day. If you’re on the go, be sure to carry a water bottle with you and try to keep sipping from it and refilling it throughout the day.

2.Avoid caffeine:Caffeine can irritate your stomach and cause the achy, crampy, bloated feeling so it’s best to avoid or limit your intake during your period. In addition to caffeine, it’s a good idea to avoid sweet and carbonated drinks that can also increase bloating. A good caffeine-free option is an herbal tea. Get a cup of hot tea (i.e. ginger, green tea, peppermint, chamomile, raspberry leaf) to reduce bloating and feel better while on your period.

3.Get some exercise:Light exercise during your period can help increase your blood flow which in turn helps alleviate symptoms like bloating.

4.Sleep:Period fatigue is real and it can be further impacted by menstrual pain. If you’re feeling tired during your period, getting good rest can help your body and mind repair themselves — aim to get at least 8 hours of sleep a night.

5.Consider:Birth-control pills and hormone treatments are often used to reduce the effect of prostaglandins. However, the pill can have adverse health effects on users, so please consult your doctor about what’s best for you and your body.

Nutrition for Menstrual Cycle

It is extra essential to load up on nutrient-rich foods such as healthy fats and proteins while you’re on your period.

You’ll also want to eat a good amount of low-glycemic-index veggies and fruits to keep your blood sugar stable while providing your body with much-needed fibre and antioxidants.

As you bleed, you’ll also be losing iron and zinc, so you can replenish your body with kelp, nori and seafood. And as always, you can’t go wrong with healthy stews and soups.

Try reaching for healthier snacks like fruits and veggies or other low-sodium foods that will prevent bloating. Avoid eating processed foods and too much salt.

Other safe bets for healthy eating are proteins like fish and chicken and healthy fats like nuts and avocados. Dark chocolate is a good source of magnesium, which can help regulate serotonin and elevate your mood.

How Does Exercise Affect Menstruation?

Exercising while on your period might seem like a counterintuitive thing to do, but it can help alleviate menstrual symptoms. There are, however, some limitations to be aware of.

You’re likely to feel a little more tired the week of your period. As your hormones drop, so does your energy, and that’s totally normal. Give yourself permission to take it super easy and try lighter exercises like walking, or mat Pilates to feel your best.

Exercising while you’re on your period needn’t put additional stress on the body, cause actual physical pain or interfere with the expected processes of the cycle.

Although, exercising during the period can be quite beneficial, there’s a few things to keep in mind

1.Strenuous or prolonged exercise:This might not be good for the body when you are menstruating but it doesn’t mean you have to stop your normal training. Just be cautious.

2.Inversion-type yoga poses:These are thought by some to pull the uterus up towards the head. Although there isn’t proper scientific evidence for this theory, there’s a popular belief that this movement can cause the broad ligaments that support the uterus to stretch and compress the veins that carry blood away from the uterus. This can lead to vascular congestion and increased bleeding because the arteries that supply the uterus continue to pump blood into the area.

3.Listen to your body:Lastly, if you feel unusually fatigued, nauseous, or there is an increase in pain or discomfort, stop what you are doing and rest. Listen to your body.


The menstrual cycle is intrinsically linked with metabolic health. With a mix of diet, nutrition, exercise and period care, you can reduce symptoms of PMS like bloating, headaches, nausea, and so on while managing the long-term side effects of unbalanced hormones like diabetes and PCOS. Listening to your body when on your period in terms of what kind of exercise routine to follow can help ease cramps and symptoms of PMS. According to research in the medical industry, women of menopausal age could be more inclined to central and visceral obesity while for menstruating women, fluctuations in oestrogen and progesterone hormones during the menstrual cycle impact glucose metabolism and insulin sensitivity.

Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns and before undertaking a new health care regimen including making any dietary or lifestyle changes.



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