A common complaint that many women have right before and during their period is increased appetite.
But, why do women feel hungrier during their period? Do you burn more calories on your period? How many calories do you burn on your period? Do you need more calories on your period?
In this article, we will look at the effect of your period on how many calories you burn and whether you need to eat more during your period.
We will look at:
- Do You Burn More Calories On Your Period?
- Do You Need More Calories On Your Period?
- Does Exercise Make Your Period Stop?
Let’s jump in!
Do You Burn More Calories On Your Period?
There hasn’t been much research looking specifically at changes in energy expenditure during your period. In other words, few research studies have specifically looked at the question, “Do you burn more calories on your period?”
One study found that there is quite a bit of individual variability in your resting metabolic rate, which refers to the number of calories you burn at rest during the menstrual cycle.
In other words, some women have quite a bit of fluctuation in the number of calories they burn during their period versus at other phases of the menstrual cycle, whereas other women seem to have a pretty steady resting metabolic rate throughout the menstrual cycle.
For example, some women showed as much as a 10% variation in their resting metabolic rate at different points of the menstrual cycle, whereas other women had as little as 1.7% variation across the cycle.
To put this into perspective, if your resting metabolic rate is 1200 calories per day, this would mean that you could potentially have a difference of 120 calories per day or as little as 20 calories per day.
Another study corroborated these findings, demonstrating that about half of the women in the study group exhibited very little variation in basal metabolic rate (BMR)—along the lines of 2 to 4%, which is on par with average fluctuation across the month for men—whereas half of the women in the study group displayed more significant metabolic fluctuations, up to 12%.
Moreover, most studies have found that even in cases where there is some amount of increase and decrease in your metabolic rate throughout the menstrual cycle, you are not burning more calories during your period.
Rather, you actually burn more calories during the luteal phase of the menstrual cycle, which occurs between ovulation and your period, and metabolic rate seems to be the lowest during the follicular phase.
It is also important to note that taking oral contraceptives (birth control pills) may eliminate cyclical fluctuations in your metabolic rate during your menstrual cycle.
For example, one study investigated the fluctuations in BMR in women taking oral contraceptives and found that there was virtually no variability across the entire menstrual cycle (roughly 2 to 4% max), which the researchers qualified as ease nullifying the normal cyclical variations.
Therefore, even if there may normally be a slight boost in metabolic rate during the late luteal phase and a slight decrease in metabolic rate during the follicular phase of the menstrual cycle, if you are on oral contraceptives, you most likely have a steady BMR throughout your menstrual cycle.
So, how many calories do you burn on your period? Ultimately, the answer is, the same number of calories you normally burn.
If you are unsure of your BMR or how to estimate how many calories you burn per day, consider using an online BMR calculator and then adding in your physical activity or exercise, or use an online calculator that takes into account activity level.
Do You Need More Calories On Your Period?
Because you do not burn more calories during your period, you do not need to eat more calories during your period.
However, it is important to eat iron-rich foods as well as foods high in vitamin C (which helps the body absorb iron) to help replace iron lost during monthly bleeding.
Although you don’t burn more calories during your period, many women feel particularly hungry right before they get their period and during the first few days of menstruation.
Studies have indeed found that appetite spikes right before getting your period, and it is particularly common to crave high-fat and high-sodium foods.
Cravings may be even worse and more persistent for women who suffer from the premenstrual dysphoric disorder, PMDD.
It is not entirely clear why there is a tendency to feel hungrier during your period and just before you get your period, though some researchers theorize that it is partly biological and partly psychological.
The body may be seeking energy-dense foods, such as fatty foods, to keep energy levels up.
Of course, depending on your weight goals and caloric needs, you may or may not want to up your food intake and indulge in some extra food.
If you are trying to control your weight and are struggling with really bad cravings and spikes in appetite before your period, you should speak with your doctor about a potential PMDD diagnosis, which can often be managed with certain oral contraceptives or other supportive medications.
Does Exercise Make Your Period Stop?
Almost every woman will attest that exercising and competing in sports when you have your period can be a hindrance.
With that said, most studies have found that athletic performance is not necessarily worse during your period, nor are there necessarily marked changes in exercise performance during the menstrual cycle.
On the other hand, some female athletes do display decreases in certain markers of athletic performance throughout the menstrual cycle, especially during the luteal phase and follicular phase.
However, a large review concluded that there isn’t enough scientific evidence to definitively support perceived changes in muscular strength, anaerobic power, endurance, etc., during the menstrual cycle and that much of the feelings of performance decrements are merely a matter of perception.
In other words, we may be apt to think we feel worse and are weaker and slower at different points in our cycle, but objectively we may not be.
Athletic performance aside, the menstrual cycle is an important part of maintaining the health of numerous systems in your body.
Having a regular period is a good sign that your hormones are well-balanced and that your body is producing enough estrogen.
Estrogen is the primary female hormone, and in addition to playing a key role in the menstrual cycle and fertility, estrogen is necessary for the health of your bones, brain, and cardiovascular system.
Although some athletes stop getting their period during heavy training, it is not normal nor optimal from a health perspective.
Amenorrhea can lead to bone mineral loss and increase the risk of osteoporosis, among other systemic issues.
Unfortunately, the absence of menstrual periods within the female athlete population is quite common, so it is often an overlooked symptom by physicians. It is just brushed off as a “normal“ part of training at a high level.
Many physicians still operate under the mindset that it’s not really a problem if young women are missing their periods, particularly during competition season.
However, in many cases, amenorrhea can last for months or years and is due to an underlying issue such as RED-S, which refers to Relative Energy Deficiency In Sport.
RED-S occurs when you are in a prolonged state of a negative caloric balance or a caloric deficit, such that you are not eating enough calories to support your energy output.
The reason that the menstrual cycle can stop when you are in a relative energy deficit is that the body needs a certain amount of energy to produce the reproductive hormones that are required for the menstrual cycle.
From a biological or survival standpoint, when there is a relative lack of calories coming in for the number of calories that are being expended, the body starts to go into “survival mode“ and conserve energy where possible so that enough energy and calories will be available for vital life processes.
One of the more elective energy-requiring processes that can be turned off to conserve energy output is the menstrual cycle.
Moreover, if your body is not getting enough calories to sustain your own normal biological functions, then it does not make sense to add the energy-demanding process of growing a fetus.
Thus, temporary infertility (if not more long-lasting) is a common consequence of RED-S, caloric restriction, or overexercising.
For this reason, if you are not getting your period regularly, speak with your gynecologist or work with a nutritionist to look into your diet and energy balance.
It may be a pain, but your period is important for your health.
For more information on exercising during your period, take a look at our guide: Running On Your Period, How Your Menstrual Cycle Affects Your Running Game.