The Space Between Reaction and Regulation
Nutrition•No. 04 of 15
Protein and Neurotransmitter Precursors
Every neurotransmitter the nervous system uses is built from an amino acid. Adequate protein is not a fitness question. It is a signalling-molecule question.
The Direct Line From Plate To Brain
Tryptophan becomes serotonin. Tyrosine becomes dopamine and norepinephrine. Glutamine becomes GABA under the right conditions. The precursors do not arrive spontaneously; they arrive from food. Long-term inadequate protein reduces the raw materials available for the exact chemistry the nervous system uses to feel, focus, and decide.
Why This Is Usually Under-Thought
Protein has been discussed for decades in the language of muscle. That framing has quietly caused many people to eat less of it than their nervous system needs. Adequate protein tends to sit around 1.2 to 1.6 grams per kilogram of body weight per day — higher for older adults, active people, and those under sustained stress.
The Practical Move
Anchoring each of two or three main meals around 25–40 grams of protein tends to shift how the day feels: steadier mood, less afternoon crash, easier evening regulation. The intervention is small. The change in Navigation Capacity, over weeks, is not.
“The neurotransmitters a nervous system runs on are built from the amino acids it was recently given.”