Hair Fall and the Keto Diet: Understanding the Connection
Hair fall is common in both men and women. But why does hair loss start after beginning a keto diet? About 80% of hair fall is connected to mental health. Stress is almost always a factor in hair loss cases.
Hair growth follows a cycle with three phases:
Anagen (Growth Phase) Hair remains in this phase for the longest time. Catagen (Transition Phase) A short phase lasting about 1–2 weeks. Telogen (Resting Phase) Lasts around three months before new hair growth begins.
People with healthy hair mostly stay in the anagen phase. However, stress, chronic inflammation, and tension can disrupt this cycle, pushing hair into the catagen phase, where it remains inactive for weeks or even months. This delay results in sudden hair loss after a few months.
Chronic Inflammation and Hair Loss
Inflammation is often overlooked as a cause of hair loss. One of the most underestimated causes of chronic inflammation is obesity. Obesity is not just a physical condition—it is a disease and an inflammatory state. In about 90% of hair fall cases, individuals are overweight, struggling to lose weight, or dealing with autoimmune diseases, arthritis, gut issues, or skin rashes. The body perceives these conditions as stress and reacts accordingly.
If a person has a persistent rash, a slow-healing wound, or chronic illness, the body remains in a state of constant stress. This stress prevents hair follicles from exiting the catagen phase, stopping hair regrowth. The visible part of the hair is actually dead tissue, while the living portion exists below the scalp within the dermis, where it receives nutrients and sebum (a natural oil essential for hair health). When hair enters the catagen phase, both blood flow and sebum production decrease, effectively starving the hair follicle.
The most concerning part of this process is that hair does not fall out immediately. It can take two to three months before shedding becomes noticeable. For example, if someone's hair entered the catagen phase today, they might not notice hair loss until months later, making it hard to pinpoint the cause.
Metabolic Health and Hair Fall
Hair loss is also common in people with metabolic disorders such as diabetes, high cholesterol, and hypothyroidism. Hypothyroidism, especially Hashimoto’s thyroiditis, is an autoimmune condition that frequently leads to hair fall.
Why Does Hair Fall Increase on the Keto Diet?
The keto diet is generally beneficial for health, but it causes a temporary adjustment phase. The body transitions from using carbohydrates to burning fat for energy, a shift that can be stressful initially.
The body’s stress response involves several hormones, including cortisol (the stress hormone), estradiol, estrone, vitamin D, progesterone, and androgens. Individuals with obesity, metabolic syndrome, or diabetes often have chronically high insulin levels, which interferes with fat-burning hormones. Insulin forces the body to store fat rather than use it for energy.
When starting keto, insulin levels drop, and fat-burning hormones are released. These hormones help heal hair follicles and improve nutrient delivery, ultimately leading to stronger hair. However, this process takes 3–5 months before visible results appear.
Temporary Hair Shedding on Keto
At the beginning of a keto diet, the body experiences a metabolic shock. Some people face symptoms like headaches, brain fog, or fatigue—this is known as metabolic adaptation. Because the body initially perceives keto as stress, hair loss may occur 3–4 weeks after starting the diet. However, as nutrient delivery improves, hair regrowth follows.
Key Takeaway
Hair loss on keto is temporary. The diet ultimately benefits hair health, but the initial adjustment phase may lead to shedding. If starting keto, it is essential to do so under medical supervision to ensure proper nutrition and minimize side effects.