Weight loss and hair loss. What’s the connection?

Very often restrictive dieting and extreme weight loss regime are devoid of essential nutrients that are required by the human body to function properly, as a consequence of this malnutrition various pathologies can arise, one of which is hair loss. This can manifest as both acute/immediate hair loss and chronic hair shedding, or as delayed hair loss, secondary to the nutritional deficiencies encountered during the process, which can occur after six months.

Telogen effluvium secondary to dieting and weight loss

Telogen effluvium is a scalp disorder that occurs due to the premature entry of hair follicles in the telogen or the shedding phase of their growth cycle. The result is the increased rate of diffuse thinning or shedding of hair. The most common identified factors that stimulate this condition include emotional and physical stress, crash dieting, eating disorders, chronic illness, and pregnancy, etc. These stressors disrupt the normal hair growth cycle leading to their accelerated entry into the telogen phase.

Telogen effluvium after bariatric surgery, or a rapid nonsurgical weight loss, is typically apparent within the first three to six months. Fortunately, the condition is self-limited and resolves when the body adjusts to these new changes, with the hair loss not being permanent and hair eventually growing back with time. According to experts, in order to avoid this problem in the first place, a person is required to lose weight in a gradual systematic way, ideally 1% of total bodyweight per week.

Nutritional deficiencies secondary to weight loss and dieting

Weight loss dieting and hair lossIndividuals going through extreme weight loss through bariatric surgeries are particularly at risk of acquiring nutritional deficiencies that may lead to hair loss. Similarly, individuals switching to strict selective diets are also prone to develop such complaints. The most common nutritional deficiencies linked with hair loss include protein, iron, biotin, zinc, essential fatty acids, and Vitamin B12.

Protein deficiency

Inadequate protein intake can have detrimental effects on all parts of the human body, especially the hair, nail, and skin, which are primarily composed of protein. Low levels of body protein cause early fading of hair color, brittle hair strands, and increased hair loss. L-lysine is an example of one such important amino acid that is responsible for the shape and volume of hair. Inadequate levels of lysine can lead to premature hair loss and thinning. Therefore, while losing weight it is essential to ensure that foods that contain high amounts of proteins such as fish, poultry and beans, are a regular part of the meal plan.

Zinc deficiency

Zinc is also mineral that plays a major role in the maintenance and growth of skin, hair, and other parts of the body. Common causes of zinc deficiency are malabsorption, eating disorders, inadequate vegetarian diet, and renal disorders. Studies point towards the deficiency of zinc to be a precipitating factor for the development of telogen effluvium. This can be prevented by ensuring the consumption of food containing high amounts of zinc such as oysters, poultry, red meat, beans, nuts, and whole rain. Multiple pieces of literature also connect the role of zinc supplements in reversing the hair loss caused by telogen effluvium and alopecia areata.

Vitamin D deficiency

Along with mineralization of the bones, vitamin D is also required for stimulating the growth of new hair follicles. Vitamin D has also been found to have a strong association with the pathogenesis of autoimmune condition alopecia areata that causes patchy hair loss. A study published in 2019 also demonstrated that a vitamin D deficiency can worsen the hair loss over time.

Iron deficiency

Although iron deficiency primarily presents as chronic anemia, it is also proven to be associated with increased hair fall, with studies documenting that low levels of iron are a common symptoms of patients presenting with hair loss.


Achieving a healthy BMI is a major accomplishment that impacts the general health of an individual in an infinite number of ways. However, one must be cautious when deciding how exactly to achieve this goal, as an unhealthy, rapid, and excessive weight loss can bring about serious health consequences that can then downplay this accomplishment. Experts advise a healthy diet and exercise to be the most effective ways to lose weight. In case these are found to be uneffective, professional help should be sought to avoid any complications. In regards to the hair loss observed post weight loss, it has reassuringly been found to be temporary and to revert to normal once the body is replenished with essential nutrients.



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