Is it possible to lose hair when starting a low-carb diet? Yes, and there are many misunderstandings and myths about it.
Here's what you may need to know.
Temporary hair loss can occur for many different reasons, including any big dietary change. This is especially common when severely restricting calories (e.g. starvation diets, meal replacements) but it can also occasionally happen on low-carb diets.
If so it usually starts 3-6 months after starting a new diet, at which point you'll notice an increasing amount of hairs falling out when brushing your hair.
The good news is that this is only a temporary phenomenon and only a percentage of the hair will fall out (the thinning will rarely be very noticeable to others).
After a few months all the hair follicles will start to grow new hair, and when they have regrown your hair will again be as thick as before. Of course if you have long hair this could take a year or even more.
Background
To understand exactly what is happening it's necessary to know the basics about how hair grows.
Every single hair on your head usually grows for about 2-3 years at a time. After that it stops growing for up to 3 months. Then a new hair starts growing in the same hair follicle, pushing the old hair out.
Thus you're dropping hairs every day, but as the hairs are un-synchronized it's not so noticeable. You drop one hair and another starts growing, i.e. you always have about the same number of hairs on your head.
Stress and synchronised hair loss
If your body experience significant stress more hairs than usual can enter the resting phase at the same time. This can happen due to many reasons, like these:
- Starvation, including calorie-restricted diets and meal replacements
- Diseases
- Unusually demanding exercise
- Pregnancy
- Breast feeding
- Nutrient deficiencies
- Psychological stress
- Any big diet change
Then as the new hairs start growing a few months later all these formerly resting hairs will drop at almost the same time. This is called "telogen effluvium" in fancy medical terms ( read more about it), and it's relatively common.
What to do
If there's a clear factor 3-6 months before the problem started - such as giving birth or transitioning to a strict low-carb diet - you don't really have to do anything. In all likelihood the problem will be temporary.
As long as you eat a varied and nutritious low-carb diet it's very doubtful that stopping it will speed up the hair regain, it will likely happen as quickly anyway. And unfortunately you can't stop the hair loss from happening once it's started, as the resting hair follicles will drop whatever you do.
It's possible to do blood tests for nutrient deficiencies, but unless you are on a vegetarian or vegan diet (with no supplements of iron, B12) it's unlikely that they will show anything interesting.
How to minimize the risk of hair loss when starting low carb
First, temporary hair loss is relatively rare after starting a low-carb diet, most people never notice anything like it.
There are no studies on how to minimize this small risk, but it's likely helpful not to restrict calories, i.e. don't do a low-carb and low-fat diet (AKA "starvation"). Instead eat as much fat as you need to feel satisfied and not hungry, an LCHF diet.
It may also be helpful to reduce other sources of stress during your first few weeks on low carb. Sleep well, be kind to yourself in general, and preferably don't start an intense exercise program at the same time.
More
Read everything about possible side effects on low carb:
Low Carb Side Effects & How to Cure Them