Foods high in Tryptophan

Why Tryptophan matters

Tryptophan is an essential amino acid your body uses as a precursor for serotonin (a neurotransmitter that regulates mood, appetite, and satiety), melatonin (the sleep hormone), and niacin (vitamin B3). It is the least abundant of the essential amino acids in most proteins, which is why protein quality calculations often flag it as the limiting factor. Animal foods deliver the densest concentrations — turkey, chicken, salmon, tuna, eggs, and hard cheeses lead the ranking. Plant sources include soy products (tofu, tempeh, edamame), pumpkin and sunflower seeds, peanuts, oats, and spirulina. The well-known sleepy feeling after a turkey dinner is largely due to the accompanying carbohydrates increasing tryptophan uptake into the brain, not the turkey alone.

Daily intake reference

Signs of low intake

Low tryptophan intake reduces serotonin synthesis and can manifest as low mood, increased anxiety, sleep disturbances, and carbohydrate cravings. Extreme tryptophan depletion is studied experimentally to trigger temporary mood drops in people predisposed to depression. Chronic severe deficiency contributes to pellagra (the classic niacin-deficiency disease), though this is usually linked to overall protein shortfall in corn-based diets where niacin is also bound and unavailable. Most people eating a varied diet meet tryptophan needs, but restricted plant-based diets or very low protein intakes can fall short.

Best for these diets

Tryptophan is well-represented in these dietary patterns:

• High-protein
• Mediterranean
• paleo
• vegetarian