Part three of the series critically examines the role of dietary amino acids, fatty acids, and hormones in human nutrition, with a focus on their elemental ratios and epigenetic implica-tions. The analysis highlights discrepancies in food composition data, emphasising the influence of food sources, preparation methods, and environmental factors on amino acid ratios. It explores tyrosine metabolism and its impact on pigmentation, thyroid function, and neurological health, while addressing evolutionary adaptations to dietary changes.