Woman losing weight measuring waist

What Causes Hair Loss From Weight Loss?

When you decide to lose weight, you’re probably looking forward to all the positive benefits that come with it. However, for some who choose extreme diets or surgery without following doctor’s advice, it can result in negative consequences such as hair loss. Here we will discuss how hair loss from weight loss can occur as well as preventative measures and treatments you can use to combat this.


  1. Hair Loss After Dieting
  2. Hair Loss After Surgery
  3. Prevention & Treatment of Weight Related Hair Loss
  4. Conclusion

Hair Loss After Dieting

Restrictive Dieting

Restrictive diets are ones that cut out certain food groups in order to lose weight. These have been linked to a type of hair loss called acute telogen effluvium. Here, the body is placed under stress due to the weight loss and change in nutrition that your body is receiving. 

As a result of this, hair that is usually in the growth stage prematurely enters the resting phase. Typically, it takes about 3 months from the inciting incident to see the hair shedding.

A restrictive diet such as a low calorie one will result in a lack of protein. Here, amino acids which are necessary for hair growth and keratin production are not provided in high enough amounts for the body. It will prioritise vital organs and functions instead of hair growth, which is deemed non-essential if there are insufficient amounts. Similarly, deficiencies in iron, zinc, selenium and fatty acids have been connected to hair loss from dieting.

Crash Dieting

Crash dieting is the sudden or rapid loss of weight which can provide fast results but will be unhealthy for your body and mental health. Also, the weight will come back quickly and more will be gained than was lost before starting the diet. Research has linked hair loss and crash dieting since the 1970s, since the lack of nutrients have resulted in hair loss. These poorly planned diets result in a dramatic drop in weight, causing your body to go into shock.

Man checking hair for hair loss on scalp

Hair Loss After Surgery

Gastric Sleeve/Bypass Surgeries

If you’re undergoing a surgery in order to lose weight, hair loss can also occur. Again, the rapid loss of weight can cause your body to respond by prioritising your nutrients to vital functions. Gastric sleeve/bypass surgery hair loss is more likely to be just due to this shock and not a nutritional deficiency, since they should not cause an issue with how your body takes in its nutrients. 

In 2021, a study showed that 75 % of women who underwent a gastrectomy experienced some form of hair loss following the surgery. The majority of respondents noted that the hair loss occurred 3-4 months after the procedure, as with other forms of telogen effluvium.

Malabsorptive Surgeries

Surgeries like biliopancreatic diversion, on the other hand, are ones which can affect the way your body absorbs its nutrients. Not only is the stomach capacity reduced, but part of the intestine is often bypassed, causing a weakness in the absorption of nutrients. This can then increase the risk of deficiencies and related medical conditions forming. The most common of these are iron, zinc, protein, copper, and Vitamins A, C and B9.

Feet on scales as woman is checking her weight

Prevention & Treatment of Weight Related Hair Loss


The best course of action if you know you are undertaking a new diet or will be receiving a weight loss surgery is to take preventative measures to ensure healthy hair. Fad or extreme diets should be avoided, as the right balance of nutrients is needed in order to keep your hair strong and growing. Dietary restrictions for those who are vegetarian or vegan will necessitate nutrient dense foods or supplements for iron and zinc. 

If you’re looking to keep your hair healthy while trying a new diet or just want a boost, you should try Dr. Balwi’s Biotin and Keratin supplements. They are two of the most important nutrients for the production and maintenance of your hair. It helps to safeguard against shock loss and thickens the hair structure.

Safe ways to lose weight

Weight should be lost in a sustainable and gradual manner in order to prevent your body reacting to stress. Your diet should be combined with exercise in order to help with stress maintenance and the balance of your hormones. 

If you are opting for a surgery, your doctor should provide you with medical advice including a nutritional plan prior to your procedure. High protein meals and snacks are advisable in order to maintain healthy hair. 

Oral supplements may be recommended, such as iron and zinc, and it’s critical not to overdo it on other nutrients. Vitamins A, E and selenium can result in extended hair loss if found in too high quantities. A recovery schedule should also be followed, which will outline the ideal diet following your procedure.


If you have already experienced hair loss, it’s essential to confirm that it is as a result of the weight loss and not another reason. While it could just be the shock your body is experiencing at the sudden drop in weight, it could also be a nutrient deficiency which will require supplementation in order to remedy it. You can contact your doctor in order to perform tests to see if you are lacking in any specific nutrients.

If an extreme diet is causing the hair loss, the sooner you stop the diet, the sooner the hair will start to regrow. A balanced diet with exercise and the right amount of vitamins and minerals is essential to healthy hair growth. 

Stay hydrated and be gentle with your hair care routine, ease up on shampoo in order to let your hair release its natural oils and avoid high heat treatments. If the hair loss is not subsiding, then a hair transplant can help those who are looking for a permanent solution to long term hair loss.


If you’re looking to lose weight, it’s important to prioritise getting the right balance of nutrients and vitamins in order to prevent hair loss from weight loss. Before embarking on a new diet or undergoing surgery, you need to properly prepare your body for any shock that might occur, leading to hair loss. 

If you’re worried about your hair loss and are looking for a long-term result, then contact one of our experts today. With a hair transplant, you can have full, healthy hair again that lasts a lifetime.