Keto And Periods: What's The Connection?

The keto diet is a popular eating plan that involves drastically reducing carbohydrate intake and increasing fat consumption. While it is touted for its weight loss benefits, it can also have some unexpected side effects, including disruptions to the menstrual cycle. Some women who follow the keto diet experience irregular periods or even the absence of a period (amenorrhea). This is thought to be caused by rapid weight loss, which can alter hormone levels and affect ovulation. However, the impact of the keto diet on the menstrual cycle is complex and varies from person to person. While some women experience disruptions, others may find that keto helps to regulate their cycle, especially if they have underlying conditions such as polycystic ovarian syndrome (PCOS).

Keto can cause amenorrhea (periods stopping altogether)

The keto diet can cause amenorrhea, or periods stopping altogether, for a variety of reasons. One of the main reasons is that the diet often leads to rapid weight loss, which can alter the estrogen-progesterone balance and impact ovulation. This, in turn, can cause periods to become irregular or stop altogether.

Another reason for amenorrhea on the keto diet is the lack of carbohydrates. Carbohydrates are the body's main source of energy, and when they are restricted, it can lead to a decrease in the luteinizing hormone, which is involved in regulating the menstrual cycle. This can result in amenorrhea or hypomenorrhea (short, light periods).

Additionally, the keto diet can mess with leptin and other hormones associated with the menstrual cycle. When too few calories and carbohydrates are consumed, a signal is sent to the body that insufficient energy is available, which can cause a drop in leptin and other hormones.

It is important to note that amenorrhea can also be caused by other factors such as stress, low body weight, excessive exercise, or a very low BMI. Consulting with a physician before starting any diet is always recommended.

For those who have lost their period due to the keto diet, it is possible to regain it by increasing calorie intake, reducing exercise, and ensuring adequate nutrient intake. In some cases, it may be necessary to gain weight or make other adjustments to restore regular menstrual cycles.

Rapid weight loss can alter your estrogen-progesterone balance

The keto diet is a high-fat, very low-carb approach that has been linked to weight loss and other health benefits. However, it can also have a strange effect on your period. Some women who follow the keto diet report irregular periods, while others say their monthly cycle vanished altogether – a phenomenon called amenorrhea. This is likely due to the rapid weight loss that may happen on a keto diet.

Angela Chaudhari, M.D., a gynecologist at Northwestern Memorial Hospital, explains that rapid weight loss can alter your estrogen-progesterone balance and impact ovulation, causing irregular periods. When estrogen levels drop, so do progesterone levels, and this can lead to amenorrhea.

Estrogen is responsible for regulating the menstrual cycle. As weight drops, estrogen levels tend to decrease. A study found that when participants lost an average of 17 pounds, their levels of the estrogen hormones estrone and estradiol decreased by 5.7% and nearly 10%, respectively.

Progesterone is also crucial in maintaining regular menstrual cycles. While low levels of progesterone do not directly cause weight gain, they can lead to water retention or bloating, making you feel heavier. Additionally, a decrease in progesterone can disrupt the balance with estrogen, further impacting your cycle.

To summarise, rapid weight loss can disrupt the delicate balance of estrogen and progesterone, leading to irregular periods or even amenorrhea. This disruption is not exclusive to the keto diet but can occur with any diet or lifestyle change that results in rapid weight loss.

Calorie restriction can interfere with the female reproductive cycle

Caloric restriction, or consuming fewer calories, can interfere with the female reproductive cycle by disrupting the hypothalamic-pituitary-gonadal (HPG) axis, which regulates the release of reproductive hormones. This disruption can lead to hormonal imbalances, affecting ovulation and menstruation.

The HPG axis is a complex interplay between the brain and reproductive organs, involving several key hormones. Caloric restriction can impact this axis in several ways:

• Reduced Estrogen Levels: Estrogen is a critical hormone for regulating the menstrual cycle and maintaining reproductive health. Caloric restriction, especially when coupled with rapid weight loss, can lead to decreased estrogen levels. This reduction in estrogen can disrupt ovulation and lead to irregular or absent periods.
• Altered Hypothalamic Signaling: The hypothalamus, a region in the brain, plays a crucial role in regulating reproduction. Caloric restriction can affect the release of hormones like gonadotropin-releasing hormone (GnRH), which stimulates the pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These hormones are essential for ovulation and the preparation of the uterus for pregnancy.
• Impaired Ovarian Function: Caloric restriction can directly impact the ovaries, leading to reduced follicle development and ovulation. It may also affect the production of reproductive hormones, such as estrogen and progesterone, which are necessary for maintaining regular menstrual cycles.
• Delayed Puberty: In some cases, severe caloric restriction during adolescence can delay the onset of puberty. This delay is often associated with reduced levels of reproductive hormones and can have long-lasting effects on reproductive health.
• Increased Risk of Infertility: Caloric restriction, especially when coupled with excessive exercise or very low body weight, can increase the risk of infertility. This is often related to hormonal imbalances and ovulatory dysfunction.
• Impact on Pregnancy: Caloric restriction during pregnancy can have significant impacts on fetal development and maternal health. It may lead to intrauterine growth restriction, increase the risk of pregnancy complications, and affect the long-term health of the offspring.

Lack of carbs can lead to amenorrhea or hypomenorrhea (short, light periods)

The keto diet is a high-fat, very low-carb approach that has been linked to weight loss and other health benefits. However, it can also have a strange effect on your period. Some women who follow the keto diet report irregular periods, while others say their monthly cycle vanished altogether. This phenomenon, where a person stops having periods, is called amenorrhea. In some research, 45% of female participants reported menstrual dysfunction after adopting keto.

One reason for this may be the quick weight loss that can occur on a keto diet. A drop in estrogen levels caused by weight loss can lead to irregular or absent periods. Additionally, body composition changes, such as weight loss, can alter GnRH (gonadotropin-releasing hormone) levels, which can disrupt ovulation and lead to amenorrhea.

Another factor contributing to menstrual irregularities on the keto diet is the lack of carbs. Extreme carbohydrate restriction may lead to changes in the luteinizing hormone, which is released by the brain and contributes to regular ovulation. When carbs are restricted, and the luteinizing hormone is compromised, it may cause amenorrhea or hypomenorrhea (short, light periods).

It's important to note that hormonal changes due to rapid weight loss or other dietary changes can also affect the menstrual cycle, regardless of whether someone is following the keto diet. Additionally, missed or abnormal periods can be a sign of a larger health issue, so it's recommended to consult a doctor if periods become irregular.

Keto can be beneficial for women with polycystic ovarian syndrome (PCOS)

The ketogenic diet has been shown to be beneficial for women with polycystic ovarian syndrome (PCOS). PCOS is a common endocrine disorder in women of reproductive age, characterised by irregular ovulation or anovulation, high levels of androgens, and the presence of polycystic ovaries. It is often associated with obesity, insulin resistance, and high levels of insulin.

The keto diet is a high-fat, very low-carb approach that has been linked to weight loss and other health benefits. For women with PCOS, keto can help decrease inflammation and insulin resistance, which are often to blame for higher than usual insulin levels. Losing weight on the keto diet can also help with PCOS symptoms.

A small study published in the *Journal of Translational Medicine* in February 2020 found that overweight women with PCOS who followed the keto diet for 12 weeks lost a significant amount of weight and saw a decrease in the ratio between LH and FSH, which is a healthier balance between the two. Another small study, published in the *Nutrients journal in October 2022, found that the keto diet helped improve metabolism and ovulatory dysfunction in participants with obesity and PCOS.

A pilot study published in *Nutrition & Metabolism* in December 2005 found that a low-carbohydrate, ketogenic diet led to significant improvements in body weight, percent free testosterone, LH/FSH ratio, and fasting insulin in women with obesity and PCOS over a 24-week period. Two women in the study became pregnant during the study despite previous infertility problems.

The keto diet can be a valuable non-pharmacological treatment for PCOS, but more research is needed to verify its effects, especially over longer periods.

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