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Cycle A-Z

Anorexia and the menstrual cycle

by Nicole Telfer, Science Content Producer
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Top things to know:

  • Any person—all sexes, sizes, and ethnicities—can have an eating disorder
  • Eating disorders, especially anorexia nervosa, can impact your menstrual cycle and even cause your period to stop
  • When your period stops due to eating too little or exercising too much, this is a warning sign that your body is not functioning correctly, and should not be taken lightly

Eating disorders are mental health conditions, and come in all different shapes and sizes. There are many different types of disordered eating patterns—some involve extreme restrictions of food intake, while others involve eating large amounts of food in a single sitting. Even less common, there are eating disorders in which people consume non-food items. Regardless of the type of eating disorder, the common result among all eating disorders is that they cause serious physical, physiological, or social impairments (1).

People often think of emaciated models when they think of eating disorders, but this is not the only way that someone with an eating disorder will look. Not everyone who has an eating disorder is really thin—just as not everyone who is thin has an eating disorder. There are many different types and presentations of eating disorders, which affect people of every ethnicity (2). Particularly in North American culture, there is still a media narrative that views weight loss positively and praises very lean (and often unattainable) physiques.

Anorexia nervosa has the most measurable effects on the menstrual cycle. Other types of eating disorders (like bulimia nervosa, restrictive eating disorders, orthorexia, and binge-eating disorder) can also impact menstrual cycle health.

What is anorexia nervosa?

The crux of anorexia nervosa is restricted energy intake leading to significant weight loss. A person with anorexia often has an intense fear of gaining weight or fat, and a disturbance in the way one's body shape is perceived (1). People with anorexia will often not perceive the seriousness of their own low body weight (1). This disorder is further classified into two types: the restrictive type versus the binge-purge type.

The extreme weight loss from restrictive anorexia nervosa happens through restricting the intake of energy/food. This is done through dieting, fasting, and/or excessive exercise.

When someone has binge-purge type of anorexia nervosa, in accompaniment to restricting food intake, they also perform recurring binge eating or purging episodes. This includes behaviors such as self-induced vomiting, or the abuse of laxatives, diuretics, or enemas.

How does anorexia affect the menstrual cycle?

For a long time, amenorrhea—a cessation of a menstruation for over three months—was necessary in order to receive a diagnosis of anorexia nervosa (3). However, this criteria have been changed, and amenorrhea is no longer required to make a diagnosis. Many women with low body weights still continue to get a regular menstrual cycle (3-5). Also, the previous definition could not be applied to men, prepubertal girls, people taking hormonal contraceptives, or people who are postmenopausal (5).

People with eating disorders often experience amenorrhea due to extreme weight loss and starvation of the body (1). This particular kind of amenorrhea is called secondary amenorrhea. If the patterns of restrictive eating happen before the onset of puberty, this can cause a delay in the timing of the first menstrual period—primary amenorrhea (1).

During states of undernourishment, the body does not have enough “fuel” to run properly, and has to prioritize which bodily functions are the most important to life. Processes that are not essential to staying alive—like growth and reproductive function—may get less energy (6). The functionality of the hypothalamus, the control center in your brain which regulates many of the hormonal fluctuations within the body, can become suppressed, and normal hormonal fluctuations like those that regulate the menstrual cycle may be altered or halted (5).

However, not everyone who is anorexic or is in a prolonged energy deficient state will be amenorrheic. Some people will have menstrual periods of normal length, and some people may experience oligomenorrhea (long, unpredictable cycles from 30 to 90 days) (4,5).

Functional Hypothalamic Amenorrhea (FHA) is the most extreme form of menstrual disturbance that can occur from a chronic restricted energy balance (5). When someone has a negative energy balance, the levels of hormones released from the hypothalamus may change (5). (Click here for a quick refresher on how normal functioning reproductive hormones change throughout the cycle).

Gonadotropin releasing hormone (GnRH), which is normally released in pulses from the hypothalamus throughout the day, can decrease in frequency due to extreme energy restriction (5,7). With less GnRH, the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) is altered in timing and in amounts (5). Without enough stimulation from these hormones, ovarian follicles—the sacs that contain your eggs in the ovary—do not receive enough stimulation to grow, adequate levels of estrogen are not produced, and ovulation may not occur. People with FHA often demonstrate low estrogen, low progesterone, an absence of LH and estrogen peaking around ovulation, and no menstrual period (5).

In amenorrheic people with severe restricting eating disorders, the period itself acts as an extra vital sign — a barometer for health. Its absence indicates that the body cannot maintain itself, and is failing to function normally. This is a warning sign, and should not be taken lightly.

Once treatment progresses and energy deficits are improved or restored, a return of menstruation and normal hormone cycling is a positive indicator of health.

It’s interesting to step back and take a more evolutionary view of why someone with chronic energy deficiency would lose their menstrual cycle. Pregnancy is an extremely energy-demanding time, and if someone cannot support their own body functions, that person could not likely support another body growing inside of them, requiring even more energy. Losing your period in times of low energy intake could be seen as a precautionary evolutionary function.

The effects of anorexia on the whole body

The health consequences of eating disorders may be profound and affect the whole body. In cases of anorexia, where body weight is significantly low, many of these changes are due to the effects of starvation. Vital signs, such as heart rate, blood pressure, and temperature are all often low, and arrhythmias (abnormal heart rate patterns) are also possible (1). Many of these changes are reversible when a person recovers and improves their body weight and nutritional intake — but some damage, like bone density loss, may be more persistent (1).

People with eating disorders, particularly anorexia nervosa, are more likely to have some concurrent psychological disorders such as obsessive-compulsive traits, depression, anxiety, social phobias, and perfectionistic pursuits. They are more likely to be high-achieving, and to express rigid control over their emotions, environment, and thinking patterns (1,8,9). The internal drive to continually lose weight and the fear of gaining fat usually do not decrease with actual weight loss. A vicious cycle can develop, where the person becomes even more fixated with losing more weight as their weight continues to fall (1). People with the binge-purge types of anorexia are often more spontaneous and more likely to abuse drugs and alcohol (1).

It is estimated that 1 in 20 people with anorexia die from the illness (10). However, this statistic could be on the low side, as eating disorders are often under-reported or under-diagnosed. Although this may seem low, the chances of dying from an eating disorder like anorexia are higher than the chances of dying from any other mental illness or disorder (11,12). Of the people who die from anorexia, 1 in 5 of those deaths are from suicide (13).

Less than half of surviving anorexia patients make a full recovery, and a fifth maintain a chronic eating disorder (10).

Why are eating disorders underdiagnosed and undertreated?

We asked Anna Ezell, a Licensed Clinical Social Worker and eating disorder specialist who practices psychotherapy at an eating disorder treatment center, for her input.

Early identification and treatment of anorexia nervosa significantly improves the rate of recovery. However, people with eating disorders typically delay seeking treatment for approximately 8 years. This suggests that people with eating disorders experience significant barriers to seeking help. Stigmas about eating disorders and a lack of knowledge within the general population, as well as the medical and professional counseling community, continue to persist. This lack of education creates a vacuum in which people may go years being treated by a professional without the eating disorder being identified.

As an eating disorder specialist, I have too often heard the story of, “My doctor told me I needed to lose 20 lbs in order to be healthy” as a precursor to the behaviors that can quickly spiral out of control. When returning for a follow-up, the patient is praised for their weight loss despite the fact their body may be shutting down from lack of nutrition. In order to adequately treat and prevent this illness, we have to insist on proper eating disorder education within our communities.

Eating disorders, particularly anorexia, are ego syntonic in nature, and someone impacted by anorexia may be highly resistant to getting help. The restrictive behaviors feel good, and unlike with other addictions, the behaviors an anorexic experiences are reinforced by society and the community at large. We are inundated on a daily basis with images of very thin women and a weight-loss industry that benefits from the promises losing weight provides.

In the United States, eating disorder specialists tend to be located in metropolitan areas, so this is a barrier to treatment for people in rural areas. Once someone does find treatment, they may be denied coverage by their insurance company or be cut-off from services too soon. Treatment is prohibitively expensive. Specialized treatment at an eating disorder facility in the US typically ranges from $500 per day to $2,800 per day, with the average cost for a month of inpatient treatment being $30,000.

Getting help

Eating disorders are serious mental illnesses. If you are struggling with eating or are feeling overwhelmed by attainable physical goals, seek help from a healthcare provider, counsellor, therapist, family member, or friend. If you live in the United States, consider contacting the National Eating Disorder Association.

Download Clue to track your menstrual cycle.

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