Dec 3, 2023

Does Fasting Cause Hair Loss?

Yup, fasting is connected to hair loss. Here's how.

Formulate user Julie has some questions about fasting and hair loss:

Ok, so this is a long story - a friend of mine who I've been close to for years and years does intermittent fasting. We both had babies at the same time, and we both gained weight. And now we're both in the process of trying to lose the weight. She swears by intermittent fasting, and said that she did it after her prior kid was born, but also has been saying that her hair fallout has gotten worse. I asked her if she thought it was connected to the fasting, she said no, she thinks it's her shampoo, but I'm kind of skeptical. I know that she uses some really nice products on her hair that are pretty much universally loved. And she's been using the same stuff for years, and never complained about this before ... except the last time she was fasting, when she was last trying to lose weight. Neither of us think that the hair loss is the normal stuff you experience postpartum, because it's been almost two years since she gave birth. I really think it's the fasting. I want to say something to her, but don't know how to, because I'm not a nutrition expert. Any thoughts about what I can tell her about how hair loss could potentially be impacted by her fasting? 

Hey Julie, thanks for writing in! This sounds like a hard situation, and we're really hoping that the info we can provide will be helpful. 

According to Registered Dietitian Jess DeGore, the founder of Dietitian Jess Nutrition LLC, hair loss can be connected to fasting. 

"Adequate nutrition is needed to maintain healthy hair," says Jess. "Restricted diets such as intermittent fasting often cause nutritional deficiencies that can be evidenced physically. The longer the fast, the more likely your body will not be acquiring the nutrients it needs to maintain physical health, including healthy hair." 

When asked, Jess said point blank that she doesn't recommend engaging in fasting. She says that most of the time when people go long periods without food, they just make up for it during their next meal, ultimately defeating the purpose of the fast. 

Here's what complicates things further: while a person who fasts could very well end up consuming the same amount of food, their body still has to deal with the consequences of having not been fed while they were fasting. "I would leverage that the longer the fasting period, the more likelihood for issues," says Jess.

And depending on how long the person was fasting, the body might be struggling to maintain its normal functions -- it's not just about the pure energy we get from food, it's also about consistent access to certain macro and micronutrients that allow the human body to keep doing its thing. 

"Hair follicles need nutrients to function properly and allow to turnover to promote hair growth," shares Jess. "The specific vitamins associated with hair growth include biotin, vitamin C, iron, vitamin D, zinc, and selenium." 

And the hair loss might just be a part of some bigger issues  - being deficient in these vitamins won't just cause hair loss. 

Hair loss can be a sign of serious nutrition problems 

Not getting enough biotin can lead to scaly, dry skin. It'll also cause you to grow brittle nails that are easily broken. 

A vitamin C deficiency can cause your gums to bleed easily, and can make you more prone to infections, ranging from the common cold to athlete's foot. 

A lack of iron is associated with anemia, which means that you have a low red blood cell count, and a lack of oxygen in your blood. This can make you feel tired and weak all the time, no matter how much you rest - your body doesn't have access to the oxygen it needs to properly function.  

Being deficient in Vitamin D can cause your bones to be weak and brittle. This can result in bone pain, and overall feelings of fatigue and weakness.

A lack of zinc in your body can prevent wounds from healing properly. Given that open wounds increase your susceptibility to infection, a zinc deficiency combined with a vitamin C deficiency could have some serious consequences to your overall health. For kids, a zinc deficiency is also linked with an inability to grow. 

And finally, a lack of selenium can cause muscle tenderness and overall fatigue. 

For a lot of people, hair loss serves as a canary in a coal mine - it's the thing that signifies that there's something wrong going on in the body that they need to attend to. If you're experiencing hair loss, your body has already been in deprivation mode for at least 6 to 8 weeks - it takes a while for the hair loss to become obvious enough to notice (hence why Jess says not to bother with fasting in the first place. The nutritional consequences can be pretty serious, and are tough to notice).

For folks who have noticed hair loss as a result of fasting, Jess recommends working with a dietitian and a doctor to get blood work done, so you can see exactly what nutrients you might be deficient in. The doctor and the dietitian will then be able to help you develop a plan to correct these deficiencies.

Nutritional supplements might be involved in correcting deficiencies, but you can't keep fasting and rely on supplements alone to get well. "For someone who wants to opt for supplementation they should know that nutrients are best absorbed with food," says Jess. "Also the FDA does not regulate supplements so you can't be certain what you are paying for is what you are getting. Not all supplements are created equal."

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