Temporary hair loss
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).
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 even if you should be so unfortunate, this is only a temporary phenomenon. And only a percentage of your 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 you have regrown your hair it will be as thick as before again. Of course, if you have long hair this could take a year or even more.
To understand exactly what is happening it’s necessary to know the basics of how hair grows.
Every single hair strand on your head usually grows for about 3-5 years at a time. After that it stops growing for up to 2 months. Then a new hair strand starts growing in the same hair follicle, pushing the old hair out.33
Thus, you’re losing hair every day, but as the hair strands are unsynchronized this is not so noticeable. You lose one hair and another starts growing, so you always have about the same number of hair strands on your scalp.
Stress and synchronized hair loss
If your body experiences significant stress, more hair strands than usual can enter the resting phase at the same time.34 This can happen for many reasons, like these:
As the new hair strands start growing a few months later all these formerly resting hair strands 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 was an obvious triggering 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 unlikely 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 has started, as the resting hairs will fall out whatever you do.
It’s possible to order blood tests for nutrient deficiencies, but unless you are on a vegetarian or vegan diet (with no supplements of iron or vitamin B12) it’s unlikely that they will show anything interesting.35However, if you have prolonged hair loss despite consuming adequate calories, especially protein, and there is no other obvious reason, then you may want to check with you doctor to make sure there aren’t any rare medical conditions that may be contributing.
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.36
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 (which your body may perceive as starvation). Instead, eat as much fat as you need to feel satisfied and not hungry, an LCHF diet.37
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 (wait at least a couple of weeks).