Abstract
Dietary planning begins with energy: a requirement is estimated, divided among carbohydrate, fat and protein, and filled with foods. While protein enters as grams, the nine essential amino acids (EAAs) never appear as separate targets, although reference values exist for each. We propose to reverse the sequence: the plan begins with the nine EAAs, proceeds to the real foods that carry them and the gaps those foods leave, and sets energy last. Three arguments support this order. First, the two starting points are not symmetrical. A 2,000 kcal budget can be filled with 517 g of sugar that supplies no EAA, or with 738 g of white bread that leaves lysine at 66% of requirement; the smallest amount of a protein food that meets all nine EAAs costs 10–53% of that energy and brings other nutrients with it. Second, the EAA requirement is the more stable and the more urgent target. Within one person, energy intake and expenditure vary widely from day to day, and both shortfall and excess are buffered at once by dedicated stores in glycogen and adipose tissue; the EAA requirement follows body weight and is set as a minimum. Body protein turnover recycles amino acids several times over each day, but recycling does not replace the EAAs that are oxidised: there is no dedicated EAA store, and a shortfall is covered by net breakdown of functional body protein. Third, the EAAs therefore have the shortest planning interval of the essential nutrients: they are best completed within the day, whereas nutrients with true stores can be balanced over the week; and because they come only in protein foods and form a nine-part target, meeting them assembles the meal and its nutrient package. Protein grams do not substitute for the nine targets: two ordinary 2,000 kcal days with the same protein, about 0.8 g/kg, leave lysine at 85% of requirement on a grain-dominant day and meet all nine EAAs on a legume and rice day. The framework therefore does two things. It secures the floor, the daily EAA condition without which the organism cannot maintain itself, and it raises the ceiling, because meals built from combined, EAA-dense foods, with carbohydrate eaten together with protein, make a healthier meal more likely. We define adequacy as at least 100% of the requirement for each EAA, corrected for digestibility, within the day, recommend completing them within each meal wherever possible, and translate the framework into four steps: Select, Combine, Complete, Adjust.