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Does Weight Loss Really Cause Hair Loss?

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No one wants to lose their hair.

But unfortunately it can be experienced by anyone at any time. As you age your hair naturally get thinner – it’s an inevitable part of the ageing process.

But what about weight loss – can that have an effect on hair?

In this article we take a look. Here’s what we’ll cover…

  • Weight loss basics
  • Is there a connection between dieting and hair loss?
  • How can you fight hair loss when losing weight?

Weight Loss Basics – Energy Balance

Fat loss has one fundamental rule – energy balance.

When you’re looking to shred fat and drop inches you need to take in less calories than you burn off through day-to-day activities and exercise.

This process of negative energy balance or calorie deficit makes your fat cells release some of their stored energy to make up for the lack of incoming calories. And by doing so you begin to lose fat and all -of-a-sudden your pants start to feel less tight around your middle.

If you don’t achieve a calorie deficit then your fat cells just don’t release the signal to open up and pour out that stored energy.

What Causes Hair Loss?

According to the American Academy of Dermatology (AAD) there are a number of reasons why you might start to lose your hair.

Firstly, there’s androgenetic alopecia which is otherwise known as pattern baldness.

This one is often referred to as ‘male’ pattern baldness but can in fact affect both men and women. It is characterized by a receding hairline, balding of the crown and general thinning of the hair on top of the head and scalp.

Alopecia areata – sudden hair loss characterized by one or more bald spots on the scalp and caused by autoimmune disease – a immune system malfunction where your body attacks your hair follicles.

The last condition, and probably the most important in terms of weight loss is telogen effluvium. 

This is caused by a higher-than-usual amount of hair follicles being in the dormant phase of development than in the growth phase. Subsequently, as hair thins and sheds there isn’t any new hair ready to take its place.

This one isn’t necessarily permanent and can be triggered by any number of things:

  • Stress
  • Pregnancy
  • Hormonal changes
  • Medication
  • Illness
  • Nutritional deficiency from a poor diet

Because of the link with nutrition deficiency, hair loss due to telogen effluvium is said to be closely related to weight loss too.

Young pretty woman brushing her hair and realizing that her hair is falling out

Key Point: Hair loss can occur for any number of reasons – genetics, stress, poor diet or hormonal changes to name just a few.

Hair Loss and Weight Loss – Is There a Connection?

Hair loss due to losing weight might be more common than you’d think.

And there’s a definite relationship between rapid weight loss and hair loss.

Drastic dieting might cause hair loss

Telogen effluvium can occur when you drop your calories down too low and you lose weight quickly. It is particularly common in eating disorders such as anorexia nervosa.

One of the main causes of hair loss is nutritional deficiency. If you aren’t getting the right nutrients you’ll begin to sacrifice ‘less important’ parts of your body in order to nourish the more valuable assets.

What’s more important, having nice shiny, healthy hair or making sure your liver is functioning properly?

When you’re low on energy your body pushes hair into the dormant phase – as far as its concerned, your hair can wait. Your body wants to use the small amount of energy it does have to help you stay alive.

Drastic weight loss such as with rapid dieting or very low-calorie eating plans are most likely to cause hair loss

Weight loss surgery is also associated with telogen effluvium, purely because of the stress of a major operation coupled with low energy availability afterwards.


Will you hair grow back?

For most people, yes it will.

It generally takes between 6-9 months, because it takes that long for your follicles to shift from a dormant phase to actively growing again.

In some cases though, it may take longer or some of your hair may never grow back.

There are a small number of treatments available but few are backed up with any science.

The best thing is to manage the underlying causes where you can, particularly any underlying stressors – prevention is most definitely better than the cure.

Key Point: The biggest cause of telogen effluvium hair loss is low energy availability and drastic weight loss.

How Can You Fight Hair Loss During a Cut?

Monitor your calorie deficit

The key to effective fat loss is to hit your calorie deficit, but not too aggressively.

Using a calorie counter like the one below helps you set your ‘calorie sweet spot’ which is typically around 20% lower than your maintenance calories. Any lower and you run the risk of lower-than-optimal energy.

By getting your calorie intake just right you’ll find that you shred fat quickly whilst minimizing any potential hair loss.

Maintain nutrient intake

Whilst it’s important to create a deficit to lose fat, you shouldn’t sacrifice a nutrient-rich diet whilst doing so. Keeping fruits, vegetables and plenty of healthy foods in your eating plan will help give your body everything it needs on the fat loss journey.

There’s also a fair bit of evidence to suggest that high-protein foods can help with hair development too by nourishing your hair follicles and stimulating new growth.

Zinc is important for hair regrowth

As an essential mineral, zinc is responsible for ensuring healthy skin, nails and hair.

Many dermatology experts believe that zinc has a direct, protective role in the regulating of protein structure, DNA and RNA responsible for hair follicles.

Research suggests that this is true as well.

A study published in Obesity Surgery [1] found that in obese patients that had lost hair due to rapid weight loss, zinc supplementation led to not only slowing down of hair loss, but reversal too – all patients reported complete hair growth within a 6-month period. 

Athletic young woman with brown hair and a black vest doing bicep curls with orange dumbbells


There are a number of reasons why you might lose your hair. These include illness, medication, stress or pregnancy.

In the context of weight loss, drastically low calorie diets and poor energy availability are likely to cause a specific type of hair loss called telogen effluvium.

In order to manage this, you should ensure you don’t diet too aggressively, and maintain a nutrient-rich diet that provides sufficient protein, vitamins and minerals such as zinc.

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Neve, HJ et al. Reversal of Hair Loss following Vertical Gastroplasty when Treated with Zinc Sulphate. Obesity Surgery. 1996; 6(1): 63-65