In addition to the symptoms commonly associated with menstruation—cramps, bloating, headaches, fatigue—many women report increased hunger. Does the body really need this extra energy, or is it hormones to blame, wonder the Organization for Science and Society and the Rumor Detector.
One way of knowing this is called the basal metabolic rate (or basal metabolic rate calculation), denoted by the English acronym BMR. This is the amount of energy our body expends when we are at rest.
It can be measured in multiple ways, but the most common is the amount of oxygen a person inhales and/or the amount of carbon dioxide they exhale at rest. By using the formula de Weirwe can deduce the number of kilocalories that our body burns per day at rest.
Parenthesis: the “calories” commonly referred to, and which are indicated on the packaging, are in fact kilocalories. When “calorie” is spelled with a capital C, it’s meant to denote kilocalories. Basically, 1 Calorie = 1 kilocalorie = 1000 calories.
If menstruation caused increased energy demands, then this should be observed in the BMR of these women during the period in question.
Easier to destroy than to build
Actually BMR during menstruation decreases during the bleeding period. This basal metabolic rate reaches its lowest point one week following the onset of menstruation, before constantly increase until the start of the next period. This curve seems to correspond to variations in the thickness of the endometrial mucosa throughout the cycle.
Although menstruation is, from the point of view of the person experiencing it, the most painful part of the menstrual cycle, it is actually the easiest part for the body. The uterus takes three weeks to build up a thick endometrial lining regarding 11 millimeters, full of glands and blood vessels, which is no mean feat. Getting rid of it during menstruation is much simpler.
For the body, the energy-consuming portion of the menstrual cycle is therefore the period from days 8 to 28, during which the organism creates flesh, and not days 1 to 7, when this flesh is dismantled and expelled. However, the uterus is not completely inactive. It contracts throughout the menstrual cycle, but is particularly powerful during bleeding.
So the question remains, if it’s not caused by an increased metabolic rate, why does the appetite kick in just before or during menstruation?
The fault (in part) of hormones
As early as 2012, research had established that progestins, such as progesterone, can stimulate appetite. Levels of this hormone peak regarding a week before the onset of menstruation, which helps explain the dips in the days leading up to menstruation.
In the same vein, although the BMR drops during menstruation, it is at its maximum just before. Variations in this rate during the menstrual cycle have been estimated by researchers to be environ 8 %that is 164 calories. It’s the equivalent of three-quarters of a chocolate bar, or regarding an orange and a half. Nothing massive, but enough to impact hunger before period.
However, not all the blame can be placed on the bodily changes. Eating is comforting: When you’re dealing with painful cramps or even emotions, comfort foods become especially helpful.
Verdict
Although you may feel hungry just before or during your period, it is not essential to swallow more calories. There is a small increase in caloric demand during the two weeks leading up to menstruation, but it is small enough to fit into the normal fluctuations of a diet.
