There is a common thread here. All of these things are affected by the level of serotonin. And tryptophan is also a precursor of serotonin. Studies have shown that experimenting with tryptophan supplements with moderately obese people, while on a calorie-restricted diet lost significantly more weight than people who received a placebo. Valine has a stimulant effect.
Healthy growth depends on it.
A deficiency results in a negative hydrogen alance in the body. This hormone regulates growth rate, metabolic rate, skin health and mental health. It is used in the treatment of anxiety, allergies and headaches. Tyrosine can act as a mild appetite suppressant. It may also be useful in the control of anxiety or depression.