Everywhere you turn, diet culture is offering the same advice: skip breakfast, cut carbs, drink powdered greens, and load up on protein. These tips are marketed as healthy—but when it comes to low carb and period recovery, they might be doing more harm than good. If you’re missing your period or trying to conceive, low-carb diets could actually be backfiring on your hormone health.

Many women come to us feeling confused. They want to recover their period and support fertility, but advice like going low carb clashes with what their body truly needs.

If you’ve lost your period or have been diagnosed with hypothalamic amenorrhea (HA), here’s the truth: low carb diets can block ovulation, delay period recovery, and sabotage your fertility goals.

What Is Amenorrhea, and Why Does It Happen?

Amenorrhea (missing your period) occurs when your body is under chronic stress—often due to a combination of undereating, overexercising, or both. This stress disrupts the hormonal communication between your brain and ovaries, halting your menstrual cycle.

Recent research highlights that low energy availability is the root cause of HA, impairing the hypothalamic-pituitary-ovarian (HPO) axis and halting ovulation (Dobranowska et al., 2024). Female athletes and active women are particularly susceptible due to the high physical and mental demands placed on the body.

Essentially, period loss occurs from the stress of under eating and overexercising. Communication between the brain and the ovaries becomes impaired resulting in weak signaling, and low hormone levels in the blood. The amount of stress that someone can handle before losing their cycle varies person-to-person. Some women may not experience full blown amenorrhea, but have difficulty ovulating regularly and getting pregnant.

Low Carb Diets and Energy Deficiency

I’m sure you’re wondering… If energy availability is the key factor, can I stick to my “normal” diet and just eat more? Unfortunately, this is not the case for nearly all of our clients. While many women with HA are eating what seems like a “healthy” diet—high in fiber and protein—they’re often unintentionally underfueling, especially when carbs are restricted. This combination can widen the energy gap even more.

According to Melin et al. (2016), low-energy density diets that are high in fiber are common in female athletes and can contribute to disrupted menstrual function due to insufficient energy availability.

Even if overall calories seem sufficient, diets that neglect carbs can fail to support hormone production. Ryterska et al. (2021) note that when your diet is low in carbohydrates, it may blunt luteinizing hormone (LH) secretion—one of the critical hormones needed for ovulation.

Carbs are one of the three major macronutrients, providing 4 calories per gram. They’re the body’s primary energy source and crucial for everyday activities, exercise, and more. In the case of hypothalamic amenorrhea (HA) recovery, carbs play a critical role. Researchers have established a clear link between the “continuous availability of readily oxidized fuels”, aka carbohydrates, and pulses of luteinizing hormone (LH).

🤔 What does this actually mean, though, in the context of a healthy menstrual cycle? 

When you consume enough carbs, your body uses the glucose it needs immediately. It then stores the rest as glycogen in your muscles and liver. Glycogen is the stored form of carbohydrates. This differentiation is key because higher concentrations of both glucose and glycogen support healthy ovulation in different ways.

Why Carbs Are Crucial for Fertility

To break it down further, carbs provide glucose—your body’s preferred fuel—and support the production and release of reproductive hormones. Here’s why they’re essential:

• ✅ Glucose (from carbs) signals to your body that there’s fuel available, which supports FSH and LH production—two hormones vital for ovulation.
• ✅ Glycogen (stored carbs) supports the body during times of higher demand and promotes LH sensitivity.
• 🚫 Low carb = low glycogen = impaired ovulatory signaling

In short: without enough carbs, your body doesn’t feel safe enough to ovulate.

Glucose signals to your body that there’s enough energy to support the reproductive system, promoting healthier menstrual cycles. Research shows that higher concentrations of glucose in the blood lead to increases in FSH and LH. These are two hormones necessary for an egg to develop and release (ovulation) over the course of the menstrual cycle.

In addition to this “immediate energy” being key to hormone health, period recovery also hinges upon having sufficient glycogen, the excess carbs that our bodies store away in the muscles and liver for later use. Low carb diets lead to low glycogen storage. And when glycogen is low, pulses of luetenizing hormone (LH) become less sensitive. This means that LH is not released in sufficient quantities when instructed to do so by the hypothalamus. Since LH pulses must reach a certain threshold to trigger egg release (ovulation), restricting carbs can cause the menstrual cycle to stall before ovulation occurs. This is a recipe to impaired ovulation, leading to a variety of fertility issues.

If you’re missing your period altogether, your body may be stuck in “survival mode.” It prioritizes essential functions (like keeping your heart beating) over reproduction. Adding a low-carb diet to this equation worsens the signal, keeping your body in a suppressed, non-ovulatory state.

How to Know If Low Carb Is Delaying Your Period Recovery

Ask yourself:

• Have you gone more than 3 months without a period?
• Are you eating <150g of carbs per day?
• Do you exercise 4–6 times per week?
• Do you feel anxious about eating carbs like bread, rice, or fruit?
• Do you feel cold often, experience low energy, or have disrupted sleep?

If you answered yes to any of these, your body may be under-fueled—and carbs may be the missing piece.

Cutting carbs might feel like the disciplined or “clean” choice, but if you’re dealing with amenorrhea or a missing period, it could be the very thing holding you back from getting pregnant.

The good news? Recovery is possible. And the right kind of nutrition can get you there faster than you think.

Many clients entering the Food Freedom Fertility Society know they need to increase their carb intake to recover their periods. However, implementing this change often brings anxiety, uncertainty, and doubt. If you’re unsure if you’re on the right track, struggling with physical or mental hurdles, or feeling stuck in your period recovery, our registered dietitians and support coaches are here to help.

👉🏻 Space is limited, so apply now to join this life-changing group!

🤔 Still on the fence?

Download our FREE Food Freedom Fertility Lab Guide for a deep dive into hormones and understanding why your period is missing.