What causes hair loss during dieting?

No matter what manner people use to lose weight, the more weight they lose, the more likely they are to experience some temporary hair loss. The condition is usually resolved when the person stops losing weight and gradually increases calorie intake by going on to a nutritionally balanced maintenance eating plan.

In one study reported in medical journals, nine patients experienced profuse hair loss two to five months after starting a vigorous weight reduction program resulting in weight loss of 25 to 55 pounds. Hair loss of 25% to 50% was observed. Re-growth of hair occurred within several months. Three patients had experienced hair loss closely following a successful weight reduction program on several occasions. Rigorous caloric restriction with subsequent inadequate energy supply of the hair matrix is thought to be the cause for the hair loss (2).

To put it another way, when people (or animals, for that matter) are losing a lot of weight, whether by eating less, exercising more, or stomach stapling, the body senses that starvation is not far behind. As a protective mechanism, “energy” that is normally available to less essential tasks such as hair growth is re-directed to more essential needs such as preserving muscle.

Hair loss can also be a symptom of certain medical problems such as fungal infection or disorders of the thyroid, pituitary or parathyroid glands. Exposure to some medicines and pesticide also can cause hair loss but are quite rare.

Stress and hormonal changes can also trigger temporary hair loss. Either of these conditions may accompany a weight reduction regime. Because a small amount of estrogen is produced in fatty tissue, some individuals may experience hormonal changes with weight loss. Stress can be a factor as new habits and lifestyle changes are implemented and food is no longer used as a coping mechanism.

It’s normal to lose hair at certain times of the year. You’ll notice it more at some times than others, even when you’re not dieting. If you’re one of the people who tend to have temporary hair loss with dieting, and it’s a time when you’d naturally lose some hair, it will certainly be more noticeable to you.

Lack of protein and vitamin supplementation can be a factor for some individuals during weight loss as can a low fat intake. There have been anecdotal reports that adding “Essential Fatty Acids” (also known as EFAs and sold in most health food stores) or oil (such as 1 teaspoon of olive, safflower, flaxseed, soybean, oil per day) to the diet may help, but no well-done studies are available to the best of my knowledge. Digestive enzymes and high-sulfur foods, such as eggs, have also been reported to help. It’s also important to drink adequate amounts of water each day, to keep the body well-hydrated.

1. Pi-Sunyer FX. Short-term medical benefits and adverse effects of weight loss. Annals of Internal Medicine, 1993 Oct 1, 119(7 Pt 2):722-6.

2. Goette DK; Odom RB. Alopecia in crash dieters. Jama, 1976 Jun 14, 235(24):2622-3.