Does low carb diet cause irregular menstruation?

A low carb diet is usually followed by those who want to lose weight, manage diabetes or any other specific health condition. But individual responses to a low carb diet can vary. Some people may even have side effects. Restricting the consumption of carbohydrates may affect your hormones, and in turn have an impact on menstruation. Know how a low carb diet may affect your periods.

What is a low carb diet?

A low carb diet is a dietary approach that restricts the consumption of carbohydrates, particularly those derived from sugars and starches.
Foods high in sugars (like candy, sugary beverages, and desserts) and starches (like bread, pasta, rice, and potatoes) are limited or avoided. The primary focus of a low carb diet is usually to reduce the intake of these types of carbohydrates in favour of higher proportions of fats. The concept behind a low carb diet is to encourage the body to burn stored fat for energy instead of relying on carbohydrates, explains nutritionist Haripriya N.

How does keto diet or low carb diet affect the hormones?

A diet that primarily restricts calories, including low carb diets, may disrupt hormones in some women, according to a research published in the Nutrients journals in 2017.

There are several variations of low carb diets, including the ketogenic diet (very low carb, high fat), Atkins diet (gradually increasing carb intake), and paleo diet (focuses on whole foods, including low carb options). The keto diet and low carb diets can have significant effects on hormone levels within the body.

Here are some key ways these dietary approaches influence hormones:

1. Insulin

The ketogenic diet, which is very low in carbohydrates and high in fats, can lead to a significant reduction in insulin levels, says obstetrician and gynaecologist Dr Sukirti Jain. With minimal carbohydrate intake, blood glucose levels decrease, leading to lower insulin secretion. This reduction in insulin is beneficial for people with insulin resistance or type 2 diabetes. Other low carb diets can also help stabilise insulin levels by minimising spikes in blood sugar after meals. This can promote better blood sugar control and reduce insulin resistance over time.

2. Glucagon

On a ketogenic diet, the body shifts into a state of ketosis where it relies on fats for fuel. This triggers a decrease in insulin and an increase in glucagon secretion. Glucagon helps in mobilising stored glucose (glycogen) from the liver to maintain stable blood sugar levels during periods of low carbohydrate intake.

3. Leptin

It is a hormone that helps in regulating appetite and energy balance. Ketogenic diets may alter leptin levels, potentially reducing leptin resistance and promoting satiety. Similarly, low carb diets may affect leptin levels, contributing to improved appetite control and potentially aiding in weight loss.

4. Ghrelin

Ghrelin is a hormone that stimulates hunger. Ketogenic diets may decrease ghrelin levels, leading to reduced hunger and food intake. Other low carb diets can also influence ghrelin levels, potentially helping people feel more satisfied and less prone to overeating, says Dr Jain.

5. Cortisol

Ketogenic diets may help reduce cortisol levels, particularly in people with metabolic syndrome or obesity. Lowering cortisol levels can have positive effects on stress management and overall health. Similarly, low carb diets may help regulate cortisol levels, potentially reducing stress and promoting a more balanced hormonal profile.

6. Sex hormones

Ketogenic diets may impact sex hormone levels, particularly in women. Changes in hormone levels can affect menstrual cycles and reproductive health.

How does low carb diet affect menstruation?

Here are some potential effects of a low carb diet on menstruation:

1. Positive effects

• For most women with conditions like polycystic ovary syndrome (PCOS), insulin resistance, or hormonal imbalances, adopting a low carb diet may help regulate hormone levels and improve menstrual regularity, says Dr Jain. Lowering insulin levels through reduced carbohydrate intake can have positive effects on hormone balance.
• Following a low carb diet may help alleviate symptoms of premenstrual syndrome (PMS), such as bloating, mood swings, and cravings, due to more stable blood sugar levels and reduced inflammation.
• Achieving and maintaining a healthy weight through a low carb diet can positively impact menstrual regularity, especially in cases where excess body weight or obesity may be contributing to irregular periods.

2. Negative effects

While keto diet helped with weight loss, menstrual dysfunction was a common side effect reported by participants during a 2003 study published in the Epilepsia journal.

• A sudden decrease in carbohydrate intake, particularly if the body enters a state of ketosis (as in the ketogenic diet), can sometimes disrupt hormonal balance, potentially leading to irregular menstrual cycles. This disruption may be more common in the initial stages of adopting a low carb diet.
• About 45 to 65 percent of a person’s daily calories should come from carbs or carbohydrates, according to the US Department Of Agriculture’s Dietary Guidelines. Drastically reducing carbohydrate intake can impact levels of reproductive hormones such as estrogen and progesterone, potentially affecting menstrual regularity.
• In some cases, very low carb diets or extreme ketogenic diets may lead to amenorrhea, which is the absence of menstrual periods. This can occur due to changes in hormone levels or insufficient calorie intake, says Dr Jain.

How to get your period back to normal when on a low carb diet?

If you are experiencing menstrual irregularities while following a low carb diet, there are steps you can take to potentially help restore normal menstruation:

1. Gradual adjustment

If you have recently started a very low carb and noticed changes in your menstrual cycle, consider gradually adjusting your carbohydrate intake. Gradually increasing your carbohydrate intake over time may help your body adapt more smoothly.

2. Choose quality carbohydrates

Vegetables, fruits, legumes, and whole grains are all whole food sources of carbohydrates and full of nutrients. These foods provide essential nutrients and fiber while moderating blood sugar levels.

3. Include healthy fats

While low carb diets emphasise fat intake, ensure you are consuming healthy fats from sources like avocados, nuts, seeds, olive oil, and fatty fish. Healthy fats are important for hormone production and overall health, says Dr Jain.

4. Stay hydrated

Whether you are following a low carb diet or not, drink plenty of water throughout the day. This will help to support overall health and hydration, which is important for hormonal balance.

If you have concerns about the impact of your diet, including a low carb diet, on menstrual health, reach out to your doctor.