The link between Zinc, Tryptophan and eating disorders

How you think and feel is directly affected by what you eat because our brain and body are made from molecules coming from food, air and water. Eating the right foods can improve your mood, energy levels and even boost your IQ! Changes in your diet impact your body and your mental health.

The idea that nutrition or malnutrition could play a part in developing and treating eating disorders did not come until the 1980s, when scientists realised how similar anorexia nervosa and zinc deficiency symptoms were (see table 1).

This article will find out the link between Zinc, Typthophan and eating disorders.

Let’s get started!


Zinc is the most commonly deficient mineral and critical nutrient for mental health. In addition to anorexia nervosa, many neurological disorders are linked to zinc deficiency, including depression and schizophrenia.

Anorexia Zinc
Weight lossWeight loss
Loss of appetiteLoss of appetite
Amenorrhoea Amenorrhoea
Impotence in malesImpotence in males
Skin lesionsSkin lesions
Anxiety Anxiety
Risk Factors
Females under 25Females under 25
Stress Stress
Table 1

Your body doesn’t naturally produce zinc, so you must obtain it through food or supplements. But guess what? People who have an eating disorder often choose to become vegetarian or vegan, and most of these diets are lower in zinc due to reduced intake and poor absorption.

Zinc deficiency may be one of the earliest predictors of anorexia nervosa. However, it is essential to mention that zinc supplements in the treatment of Anorexia nervosa; represents only one factor of this complex disorder.


Tryptophan is an essential amino acid and the building block of serotonin, the brains “happy neurotransmitter” that controls mood, mental health, sleep, appetite, and more. Unfortunately, the body can’t produce it, so as with zinc, it must come from your diet.

A study of 20 women showed that those with bulimia nervosa consumed more calories (39% more) and showed mood irritability due to tryptophan depletion. These results indicate that women with bulimia nervosa have an exaggerated response to short-term alterations in serotonin activity and are more prone to tryptophan deficiency.

Furthermore, starvation and excessive exercise, both part of almost all eating disorders, can influence blood’s tryptophan availability.

Food sources of Zinc and Tryptophan

Food sources of tryptophan include:

  • Oats
  • Banana
  • Dried prunes
  • Milk and cheese
  • Tuna fish
  • Chicken and turkey
  • Peanuts
  • Chocolate

 Food sources of zinc include:

  • Red meat and Poultry
  • Seafood (oysters, crab, lobster)
  • Eggs
  • Beans
  • Nuts
  • Whole grains
  • Fortified cereals
  • Dairy products

Tips to boost serotonin!

  • Sunshine 
  • light therapy 
  • Exercise
  • Meditation

The bottom line

Those prone to anorexia or bulimia have a particular need for tryptophan and zinc. When deprived of these nutrients, they are more likely to develop unhealthy reactions, including losing appetite or control.

Consuming high in Tryptophan and Zinc is crucial, but often not enough. If you are suffering from an eating disorder, talk with your health provider about supplementation and treatment options.

Patrick Holford, (optimum nutrition for the mind)

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