Tryptophan
Tryptophan is an amino acid needed for normal growth in infants and for the production and maintenance of the body's proteins, muscles, enzymes, and neurotransmitters. It is an essential amino acid. This means your body cannot produce it, so you must get it from your diet.
Protein is an important nutrient that builds muscles and bones and provides energy. Protein can help with weight control because it helps you feel full and satisfied from your meals. The healthiest proteins for weight maintenance are the leanest, meaning they have less fat and calories than other choices. The leanest protein choices are fish or shellfish, skinless chicken or turkey, low-fat or fat-free dairy (skim milk, low-fat cheese). The leanest red meat cuts are loin and tenderloin. Other healthy options are plant-based proteins.
Amino acids are either essential, which must be supplied by food, or nonessential, which are made in the body.
Function
The body uses tryptophan to help make melatonin and serotonin. Melatonin helps regulate the sleep-wake cycle, and serotonin is thought to help regulate appetite, sleep, mood, and pain.
The liver can also use tryptophan to produce niacin (vitamin B3), which is needed for energy metabolism and DNA production. In order for tryptophan in the diet to be changed into niacin, the body needs to have enough:
- Iron
- Riboflavin
- Vitamin B6
Food Sources
Tryptophan can be found in:
- Cheese
- Chicken
- Egg whites
- Fish
- Milk
- Sunflower seeds
- Peanuts
- Pumpkin seeds
- Sesame seeds
- Soy beans
- Turkey
References
Nagai R, Taniguchi N. Amino acids and proteins. In: Baynes JW, Dominiczak MH, eds. Medical Biochemistry. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 2.
United States Department of Health and Human Services; United States Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th ed.
Version Info
Last reviewed on: 2/4/2022
Reviewed by: Meagan Bridges, RD, University of Virginia Health System, Charlottesville, VA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
