Abstract: Nutrient metabolism and nutrient requirements of the human body and the corresponding recommendations of nutrition professionals are examined from a physiological perspective in a text for clinical nutritionists and other nutrition scientists. Nutrients are viewed as entities that must be consumed to delay acute or chronic manifestations of abnormal physiology. The 5 sections of the text cover: basic concepts of nutrient needs (requirements vs. recommendations; nutrient acquisition; breast vs. bottle feeding for infants); caloric bulk requirements (energy, carbohydrates, protein, lipids, dietary fiber, energy balance, high-energy foods); vitamin micronutrients; mineral metabolism; and individual needs. Brief overview are included on the controversy of feminine metabolic needs, the history of vitamins, and human fluid dynamics. Numerous appendices are included (e.g., safe and adequate daily intakes of vitamins and minerals; recommended daily dietary allowances; recommended energy intakes by height an d weight; nutrient labeling requirements; drug-nutrient interactions; food exchange lists; nutritive values of the edible parts of foods). (wz).