The Truth About Keto Diets And Hair Loss

Read Time: 15 minutes

Will A Low Carb Diet Stop Your Hair Loss?

In 2012, I did a four-month test to see if a ketogenic / low-carbohydrate diet would stop my hair loss.

This article uncovers my experience: why I did it, what went wrong, and my biggest takeaways from “low-carbing”. By the end, you should know:a

• The connection between ketosis, heart health, and hair loss
• How a low-carbohydrate diet might HELP and HURT your hair
• My biggest low-carb mistake (hint: it’s one that almost everyone makes)
• My advice for anyone trying a ketogenic diet and worried about hair shedding

Low-Carbohydrate Diets: The Latest Trend Or A Fitness Holy Grail?

When I first heard about a low carbohydrate diet, I thought I was talking to a crazy person.

It was 2012, and I was standing across from a Cross-Fitter. He rambled on about how (in two months) his new low-carb diet miraculously cleared up his acne, helped him shed 10 pounds, and even improved his mental acuity.

I walked home thinking he was brainwashed. But I soon read hundreds of online testimonials from low-carbohydrate dieters. They all shared this Cross-Fitters’ anecdotes: rapid weight loss, clearer skin, better energy.

Then came a series of studies supporting everyone’s claims. Low carbohydrate diets…

• …are associated with marked neurological improvements in epilepsy, dementia, and Alzheimer sufferers.
• …may delay or even suppress tumor growth in cancer patients.
• …could help prevent coronary heart disease – even more so than low-fat diets.

That last point got me wondering… Given heart disease’s correlation with pattern hair loss, and given that I’d yet to find a solution to my hair thinning, then maybe a low-carbohydrate diet might help me stop or reverse my hair loss.

The only way to know? To test and find out.

My results were not what I expected.

The Evidence: Why A Low-Carb Diet Might Stop Hair Loss

In short: any diet which helps prevent heart disease might also help support hair health.

Men with heart disease tend to also have pattern hair loss. And recent research suggests that baldness might even be an indicator of impending heart disease. The question is… Why?

Well, both heart disease and hair loss have a common mechanism of action: arterial calcification.

The accumulation of plaque and calcification within our arteries contributes to the development of heart disease. Similarly, the calcification of the blood vessels supporting our hair follicles contributes to hair thinning:

The net: if we want to avoid heart disease and pattern baldness, we should probably do everything we can to prevent arterial calcification. So where does a low-carbohydrate diet come into play?

Low-Carbohydrate Diets May Prevent Arterial Calcification

Interestingly, low-carbohydrate dieters may be significantly more protected against heart disease and atherosclerosis than low-fat dieters. The mechanisms why are less clear, but research suggests the protection may come from decreased blood pressure, improvements to cholesterol particle size, and a decrease in serum c-reactive protein (a benchmark for cardiovascular disease).

And perhaps the biggest “benefit” touted by low-carb advocates is something known as ketosis.

Ketosis: A Tool For Weight Loss, Reversing Arterial Plaque, And Maybe Hair Loss?

A ketogenic diet is a diet that forces our bodies into a metabolic state called ketosis. This is when we begin burning fat for fuel instead of carbohydrates.

Typically, carbohydrates are our bodies’ go-to source for energy. Once ingested, carbohydrates are stored as glycogen. When we need energy, our cells break down that glycogen into glucose (a simple sugar), which then gets broken down inside our cells to provide us with the energy we need to keep moving.

So what happens when we run out of carbohydrates? What do our bodies turn to for energy?

Something called ketone bodies. And that’s where ketosis comes into play.

Ketosis is a secondary metabolic state in which our bodies convert fat molecules into ketones which are then utilized for energy. The easiest way to put yourself into ketosis? Take away your access to glucose. Or in other words, restrict your carbohydrate intake.

Interestingly, many health benefits of a low-carbohydrate diet might be exclusively attributed to ketosis. From weight loss to neurological improvement, ketosis might actually be the diet’s mechanism of action. (Note: we can’t say for sure without more research.)

So back to hair loss… Can ketosis help?

Maybe! At least theoretically.

Ketosis May Reverse Arterial Plaque Build-Up… But Will It Translate To Hair Growth?

Case studies show that a ketogenic diet may reverse arterial plaque build-up. In other words, ketogenic diets might improve arterial blood flow and clear the way for more oxygen to reach dying hair follicles.

I was in! The heart health-ketosis connection was enough to convince me to try a low-carbohydrate diet. After all, my hair loss wasn’t slowing down. What’s the worst that could happen?

Going Low-Carb To Stop Hair Loss… But What Is A Low Carbohydrate Diet, Exactly?

This is harder to answer than you’d think. The broad definition of a low-carbohydrate diet:

Restricting your daily carbohydrate intake.

Beyond that, things get complicated.

1. If you’re restricting carbohydrates, do you replace those missing carbohydrates with other macronutrients – like protein and fat? Or do you also restrict total calories?
2. How few carbohydrates per day qualify as a “low-carb?”
3. Is a low-carbohydrate diet also a paleo diet?

Some researchers say that low-carb diets are also calorie restrictive – meaning you should be in a daily calorie deficit (eating fewer calories than you burn). Others say you should replace those carbohydrates with fat and protein so that you don’t enter a calorie deficit.

Moreover, opinions differ on where a “moderate-carbohydrate” diet stops and a “low-carb” diet begins.

• Chris Kresser suggests the low-carb marker is ~75-100 grams daily, depending on gender and activity levels
• Diet Doctor breaks up low-carb into three daily tiers: strict (under 20 grams), moderate (20-50 grams), and liberal (50-100 grams) – depending on your weight loss goals
• KetoDietApp suggests that low-carb isn’t an actual number. Instead, it’s the maximum carbohydrates you can eat fdaily while still staying in ketosis
• TheKetogenicDiet.org breaks up low-carbohydrate ketogenic diets depending on your strategy for ketosis: standard, cyclical, or targeted

And what about this whole paleo-low-carbohydrate diet thing?

A paleo diet naturally restricts carbohydrate consumption by eliminating grains and refined sugars. But not all paleo diets are low-carb.

For instance, a paleo protocol can technically include a pound of potatoes or a dozen fruits daily – both of which will net you 300-500 grams of carbohydrates and keep you out of the “low” range. Conversely, a low-carb diet can also not be paleo. It’s possible to limit carbohydrates but still eat grains occasionally. These definitions all depend on your set restrictions within a low-carb diet.

The bottom line? Everyone interprets “low carb” differently. So when you’re talking about “low carb” – you have to get more specific.

My Low-Carbohydrate Protocol To (Hopefully) Stop Hair Thinning

There’s no clear consensus on which low-carb protocol is best for your heart or hair. So I made my own plan.

Here’s how I decided to frame my low-carbohydrate protocol:

• Paleo-based. I excluded grains, refined sugars, legumes, and most dairy products. Paleo-based diets naturally eliminate most carbohydrate-heavy foods anyway, which would make low-carb dieting easier
• Ketogenic. I reduced my carbohydrate count between 40-80 grams per day. I wanted to stay in ketosis – because research suggested that ketosis might be why low-carb dieters see benefits
• NOT Calorie Restrictive. I increased my fat and protein intake to keep my total daily calories at 2,500-3,000. My goal wasn’t to lose weight – it was to stop my hair loss

My Low Carb Diet Foods

• Liquids. Water, coffee, tea, kombucha (rarely), coconut water
• Greens. Lettuce, bok choy, kale, swiss chard, brussel sprouts, broccoli – everything
• Fruits. Oranges, apples, bananas, dates, coconut, strawberries (note: while testing, I rarely ate any fruit)
• Roots. Carrots, sweet potatoes
• Fats. Olive oil, butter, coconut oil, red palm oil, avocado
• Meats. Ground beef, bison, steak, pork – everything
• Seafood. Oysters, scallops, salmon, cod – everything

Macronutrient Breakdown (% Of Total Calories)

• Carbohydrates. 5-10%
• Fats. 60-65%
• Protein. 30-35%

With all the ketogenic diet recipes floating around, this diet was easy to implement. It was a bit expensive (I was spending an extra $100 per week on meats, seafoods, and vegetables), but it was a price I was happy to pay to hopefully halt my hair loss.

To ensure I maintained my calorie count, I ran my meals through FitDay.com. I did this just for my first week of low-carb dieting – to get an idea of how much food I needed to stay at 2,500-3,000 daily calories.

How I Measured Progress: Thyroid Function, Rate Of Hair Fall

A low-carbohydrate diet wasn’t my first dietary attempt to arrest hair loss… It was more like my fifth. And at this point, I’d gotten pretty good at gauging how to measure a diet’s progress. My biggest lesson came two years prior during my vegan-hair loss experiment. My learning:

Proper thyroid function is critical to hormonal balance and hair health. Unfortunately, thyroid function is also largely dependent on diet. The wrong diet can inhibit thyroid function, exacerbate hormonal imbalances, and even accelerate hair loss.

While going vegan, I developed all the signs of something known as hypothyroidism (an under-performing thyroid). To list just a few signs:

• Poor circulation to the extremities (cold hands / feet)
• Brain fog
• Lack of energy
• Increased hair shedding

This time around, I decided to measure thyroid function regularly to avoid another hypothyroid fiasco.

Measuring Thyroid Function: Body Temperature, Resting Pulse

You don’t have to get a weekly blood panel to track your thyroid health. All you have to do is by an oral thermometer and learn how to count your resting heart rate.

Before thyroid blood panels were widely adopted, doctors used body temperature and resting heart rate to assess thyroid function. So according to these metrics, what qualifies someone as having “normal” thyroid function?

• Oral temperature – between 98.2 – 98.8 degrees Fahrenheit before lunch
• Resting pulse – between 65-85 beats per minute

If your pulse and temperature are consistently lower, you might be hypothyroid (a low functioning thyroid). If they’re consistently higher, you might be hyperthyroid (an overactive thyroid).

Measuring My Rate Of Hair Fall: Not So Simple

Unfortunately, there’s no simple way to gauge your rate of hair fall.

While research centers have hair-counting tools and 100x-zoom microscope lenses, I had neither. So I did what I could: I eye-balled it.

I know that part isn’t very scientific. But at this point, I’d become so hyper-aware of the rate of my hair shedding – how much typically fell out while taking a shower, how many strands I’d see on my pillowcase each morning, the number of hairs falling onto my desk throughout the day – that I felt okay with my measurement choice.

Any significant changes – good or bad – I was sure I’d notice.

My Metrics: Before Going Low-Carb

I’m 6’4″, lean, and very active. Before going low-carbohydrate / ketogenic…

• I weighed 195 pounds
• My mid-morning oral temperature was 97.7 degrees fahrenheit
• My waking resting heart rate was ~55-65 beats per minute
• I was working out five days per week (weight circuits, jogging, etc.).

And yes… My oral temperature and pulse rate were already low. That’s correct. Even before starting the diet, I was already symptomatic of hypothyroidism. I was actually hoping that my low-carb experiment would change that.

So let’s get onto the actual experiment. After a few trips to the grocery store and a whole new set of new meal plans, I was ready to begin.

My Low-Carb Experiment: Would It Reverse My Hair Loss?

Days 0-3

My energy levels increased. My workouts “felt” better. Someone commented that my eyes looked whiter. No reduction in the rate of my hair fall, but it was way too early to see a change anyway.

No changes in pulse rate or oral temperature.

Days 4-15

The transition into ketosis began. It wasn’t easy. I felt lethargic. My morning weigh-ins went from 195 pounds to 191 pounds. I figured it was water weight (more on this later). No change in hair fall – but still too early to tell.

No changes in pulse rate or oral temperature.

Days 16-30

My skin cleared up enormously. I always had a little acne. For the first time since high school, I stopped getting new blemishes.

However, I was still feeling tired. I starting having trouble focusing at work. I decided to reduce my workouts from five to three times per week. My morning weight dropped to 188 pounds. This concerned me – until I remembered all the anecdotes about rapid weight loss. I guess it was a part of getting used to ketosis and fat-burning.

My hands felt consistently colder. Still no change in the rate of my hair fall – but again, a month-long diet trial is nothing.

A slight decrease in average resting pulse rate: 50-55 bpm

A notable decrease in average mid-morning oral temperature: 97.0 degrees fahrenheit

Days 31-60

My skin became incredibly clear. No signs of acne, and no signs of scarring from my recently faded blemishes.

But now I was freezing. All the time. Three coworkers commented on how frigid my hands were after a handshake. They also asked if I was feeling alright.

My weight dropped to 184 pounds. When would the ketosis-driven weight loss stop? I could no longer do my circuit workouts with 25-pound dumbbells, so I started decreasing the weight to 17.5- to 20-pound dumbbells.

Resting pulse rate: 48-55 bpm

Oral temperature: 96.5 degrees fahrenheit.

I didn’t understand why my body temperature was dropping so much. While I had many signs of hypothyroidism, I wasn’t shedding any more hair. This made me believe something else was going on.

After some research I came across the term “keto flu“. It turns out many low-carbers also experience my symptoms during their transition to ketosis. This eased my concerns – especially since all the anecdotes suggested I would “breakthrough” this plateau in a week or two. I decided to keep pushing.

Days 60-75

My energy levels started to pick back up! This was exciting. And my skin stayed crystal clear – though I started producing a lot more sebum, which made my hair and face oilier. I still had cold hands and feet – but I’d sort of gotten used to it. Maybe that Cross-Fitter was onto something!

My weight seemed to stabilize at 183 pounds (twelve pounds lighter than when I started). Maybe the ketosis-driven weight loss phase was finally winding down? Keep in mind: my goal was not weight loss. My goal was to stop my hair loss.

Unfortunately, I started noticing more hair on my pillow case and in the shower drain.

Resting pulse rate: 48-55 bpm

Temperature: 96.9 degrees fahrenheit. A notable increase from the previous week.

Days 75-104

My energy levels decreased to a new low. I dropped to 180 pounds – fifteen pounds lighter than 2-3 months ago.

I decided to stop working out. I was too exhausted to walk to the gym – let alone exercise.

For no good reason, I also stopped measuring my pulse and temperature. For this thirty-day window, I tracked my resting pulse and oral temperature just once… toward the very end.

Resting pulse: 46 bpm

Temperature: 95.8 degrees fahrenheit

What I did keep an eye on: the rate of my hair fall. My hair shedding was getting worse. Hair fall increased in the shower, at my work desk, and on my pillow. What’s worse, my hair was beginning to look visibly thinner.

Was this whole low-carb thing working for me?

Day 105

While at work, I got hit with a massive headache and decided to leave early. One-hundred steps out the door I started shivering. I couldn’t make the one-mile walk home, so I hailed a taxi, walked inside, turned on all the heaters to my apartment, and decided to take my oral temperature.

It was 104 degrees fahrenheit.

I’d caught the flu for the first time in seven years.

I went to bed, slept for 18-hours straight, and woke up at 178 pounds.

Enough was enough. That was my last day trying low-carb / ketosis. The moment I recovered from the flu, I ordered (and then inhaled) a full pizza.

Low Carb Dieting Increased My Hair Loss. So What Went Wrong?

During my low-card experiment, my resting pulse rate dropped, my body temperature plummeted, I accidentally lost 17 pounds, and my hair shedding significantly increased. Reviewing my results, it’s easy to write-off a low-carb / ketogenic diet and say, “Ketogenic diets do not help with hair loss.” But it’s actually not that simple.

In fact, while going low-carb I made a huge mistake. Maybe the stupidest mistake in all my years of diet tracking.

Do you know what it is? Look at my before-after metrics. See if you can figure it out. Remember, I planned my low-carb protocol to be 1) paleo, 2) ketogenic, and 3) NOT calorie restrictive.

You see the problem?

I lost 17 pounds in less than four months. Do you think that’s normal? Especially for someone who didn’t want to lose weight? No, not at all.

When I began reviewing my data, I realized I’d probably just spent four months in a calorie deficit.

So I went back to FitDay.com. I entered in my last few days of low-carb meals from memory. I’d fallen into a routine of eating the same six or seven meals consistently, so it wasn’t hard. What I found shocked me:

I was consuming ~1,900 calories daily. I under-ate by 600-1,000 calories every single day.

How is that possible? I remember tracking my food intake over the first week. I was meeting my caloric demands. Could I have unknowingly and drastically changed my food intake just a few weeks later? Apparently so.

All that weight loss I attributed to ketosis was actually due to my long-standing calorie deficit. My end-result:

• I became more hypothyroid
• I lost 17 pounds
• I lost more hair

I was so focused on tracking my thyroid that I didn’t to track my calories.

I beat myself up over this for a long time. I was angry for botching my own experiment and worsening my health and hair along the way. How could I have been so stupid?

The experience bothered me until 2016, when a research paper revealed something shocking:

Most low-carb dieters make the same mistake.

The Low-Carb Myth: Is The Weight Loss Caused By Ketosis… Or A Calorie Deficit?

The answer? Both.

When transitioning into ketosis, it’s normal to lose some water weight – maybe a few pounds. Why? Because glycogen (the molecule used by our bodies to store carbohydrates) is also stored alongside water. Typically one gram of glycogen is stored with three grams of water. When we restrict carbohydrate intake, our bodies tap into their glycogen stores to break down glycogen into glucose for energy. A byproduct of this process? A release of all that water.

The net: if you keep calorie count the same, you should only lose a few pounds while transitioning into ketosis (depending on your glycogen stores).

Unfortunately, ketogenic diets may also lead to appetite suppression. You might feel just as satiated from an 800-calorie meal as you once felt from a 1,000-calorie meal. This makes you far more likely to start under-eating.

The end-result? Rapid weight loss… starting with water weight and ending with a calorie deficit. Hence the reason why so many low-carbers shed so many pounds effortlessly.

This concept became cemented in 2016 when researchers controlled for calorie intake and tested if a low-carb or a low-fat diet would result in more weight loss. The results? The same amount of weight loss for both groups.

In other words, low-carbers are shedding pounds because of a calorie deficit, not because of the “magic” of ketosis.

Calorie Deficits: Great For Losing Weight, Terrible For Reversing Hair Loss

Under-eating is commonly associated with the term “crash diet” – a quick and effective weight loss approach. Unfortunately, crash dieting can also lead to malnourishment. And there are two reasons why a ketogenic + calorie restrictive diet are particularly detrimental to our hair.

#1: Low-Carb Diets + Calorie Restrictive Diets Suppress The Thyroid And Increase Hair Shedding

Studies show that calorie restrictive diets inhibit thyroid function… with the biggest decreases to thyroid function coming from calorie restrictive diets that are also ketogenic.

Earlier I mentioned that our thyroid is important for our hair health. But why? To quickly summarize from a previous article…

Your endocrine system, but specifically your thyroid, is your body’s center for hormone regulation. If we have an underperforming thyroid, we’re more susceptible to hormonal imbalance, autoimmunity, depression, and a host of other chronic conditions. And if we develop a long-standing hormonal imbalance, we’re far more likely to develop heart disease, atherosclerosis, and arterial calcification… The same calcification implicated in hair loss.

#2: Calorie Restrictive Diets Increase Stress Hormones And May Trigger Telogen Effluvium

Low-calorie diets increase cortisol production – an antagonist to testosterone. (Note: for more information, read this).

Unfortunately, increased cortisol secretion combined with the malnourishment from calorie restriction can result in an aggressive hair loss condition known as telogen effluvium.

Telogen effluvium is rapid onset hair thinning. Some cases of telogen effluvium are temporary; others persist indefinitely. Telogen effluvium is also hard to diagnose since it manifests in so many patterns – patchy thinning, evenly-spaced thinning, or sometimes just accelerated hairline / vertex recession.

What’s more important is what triggers telogen effluvium. And it seems one the best ways to prevent it is to 1) avoid stress, and 2) avoid a major calorie deficit. If you’re not careful while going low-carb, you’ll walk straight into both of those problems.

My Advice For Low Carb Dieters Worried About Hair Shedding

Track your weight. Track your calories. If you’re not tracking on a regular basis, you might end up like I did: in a ketogenic calorie deficit. The signs:

• Rapid weight loss
• Decreased thyroid function (hormonal imbalance)
• Increased cortisol
• Increased hair loss

Do I think all ketogenic diets cause hair loss? No. If you’re careful enough to stay out of a calorie deficit, I think you’re far less likely to increase hair shedding or develop telogen effluvium.

With that said, I still haven’t seen many anecdotes (or evidence) of a ketogenic diet halting anyone’s hair loss.

“But A Ketogenic Diet Is How Our Paleo Ancestors Lived! And Paleo Communities Today Suffer Less From Hair Loss Than The First World!”

That second sentence may be true. However, the idea that paleolithic people lived in ketosis is nothing more than an internet rumor.

Several studies suggest that carbohydrates totaled 30-40% of paleolithic peoples’ daily caloric intake. And for those consuming fewer than 20% of total calories from carbohydrates, it was because they lived furthest from the equator – where fewer fruits grew. And guess what? That 20% carbohydrate threshold is still two-fold higher than what many “ketogenic paleo dieters” aim for today (around 10% of total calories).

Are You Ketogenic Without A Calorie Deficit And Still Hypothyroid? Consider A Natural Thyroid Supplement

Ben Greenfield – a professional endurance athlete, health researcher, and ketogenic advocate – once implied that for certain people, ketosis even without a calorie deficit may exacerbate hypothyroidism. In these cases, it might be necessary to either 1) change your diet, or 2) supplement with some form of thyroid.

This shouldn’t be surprising. Thyroid was taken out of the US food chain decades ago. Our only access to thyroid today is in the form of prescription pills. Evidence suggests that hunter-gatherers ate nose-to-tail – including animals’ thyroid glands. Thyroid supplementation has been shown to improve thyroid function, so it’s possible that occasional thyroid consumption might’ve protected paleolithic people from the same thyroid woes some ketogenic dieters suffer today.

If you abide by a paleolithic diet, want to stay in ketosis, and are worried about declining thyroid function – a thyroid supplement might help. I have no recommendations on which thyroid supplements are best.

Final Summary: Be Careful With Ketosis! Monitor Your Weight, Your Calories, And Your Hair Shedding

While experimenting with a low-carb / ketogenic diet, I experienced poorer thyroid function, rapid weight loss, and increased hair shedding. My experience wasn’t unique – many ketogenic dieters report these same symptoms.

While ketogenic diets alone don’t directly trigger hair loss, ketogenic diets suppress appetite and make dieters more prone to under-eating. The combination of ketogenic + calorie restriction has been linked to poorer thyroid function, telogen effluvium, and increased hair shedding.

My biggest piece of advice for those in ketosis: avoid a calorie deficit. And if you’re ketogenic, eating enough calories, but still struggling with hypothyroidism – either change your diet or try a thyroid supplement.