Can a weight-loss diet cause hair loss?

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Hair loss has been thought to be related to excessive weight loss. In this video, Dr. Oz explains addresses the issue of what specifically causes hair loss in men and women.
Hair loss can result from a diet that lacks vital nutrients causing malnutrition. Too few calories, or a very restrictive diet, are usually to blame. For healthy weight loss it is best to only decrease one's daily caloric intake by 500-1000 calories, and to consume a diet that consists of lean protein, fruits, vegetables, and complex carbohydrates.
Anthony L. Komaroff, MD
Internal Medicine
Diets, especially "crash" or "fad" diets, can lead to hair loss.

If you have been on a diet that does not include enough protein, iron, and other dietary requirements, your hair loss may be from poor nutrition. If you are eating a balanced diet, it is less likely that you have a nutritional deficiency.

In some situations, a nutritional deficiency is more likely. For example, the body needs only a very small amount of biotin. This is widely available in many foods. It is also produced by the natural bacteria in your intestine.

But there are foods and medicines that can keep biotin from doing its job. This can result in a deficiency. Raw eggs contain a substance called avidin. This makes biotin unavailable to the body. So any diet that includes eating raw eggs can lead to a biotin deficiency.

Antibiotics can destroy the healthy bacteria in your intestines that produce biotin. A very long treatment of antibiotics can decrease the body's supply of biotin, leading to a deficiency. And taking certain anticonvulsant drugs can increase the breakdown of biotin.

A more likely cause of hair loss with weight loss is "telogen effluvium." The stress to one's system from sudden or excessive weight loss can throw hair follicles into their resting phase. This is when many hairs are shed. Other stressors -- high fevers, childbirth, surgery -- can lead to telogen effluvium. This resting phase usually lasts two or three months. Hair growth returns to normal after that.

Because there are many causes of hair loss, it is important to see your doctor. The right treatment depends upon the correct diagnosis. If your doctor suspects a nutritional deficiency, tests can determine what you need to become balanced again.
Harvard Medical School A Woman's Guide to Hair Loss and Excess Hair

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Harvard Medical School A Woman's Guide to Hair Loss and Excess Hair

How much time do you spend taking care of your hair each day? Multiply that time by the estimated number of days in your lifetime and you will get some idea of the importance of hair in your life. ...
John La Puma
Endocrinology Diabetes & Metabolism
Yes, it can: that's been commonly described. Supplementary vitamins don't prevent hair loss associated with rapid, significant weight loss. And some dietary supplements are high in vitamin A which can exacerbate the hair loss. Fortunately, the hair can grow back! Read more at the

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.