An updated and expanded version of Davis' first work, a nutrition text (Vitality Through Planned Nutrition, 1942)--of interest chiefly for its information on the physiology of eating, since the balance was further developed by Davis herself in later books. British nutritionist Gildroy, responsible for the new material, has kept the textbook tone in explaining exactly how the body uses food--which we need to know, she maintains, so that the ""rules"" of healthy eating can be flexible and adaptable. After the introductory discussion of ""Digestion and Enzymes"" come: particulars on ""What Vitamins Can Do For You"" (deficiency diseases; requirements and sources); the role of ""Air, Water, and Minerals"" (how the heart, lungs, and kidneys work; why we need trace elements); and a round-up on ""Health For the Family"" (the nutritional needs of different age groups, and special diets for special needs--here, pregnant women, vegetarians, athletes, dancers, and models). Also featured is Davis' best advice on prepating food so as to minimize nutrient loss (for which she set the standard in Let's Cook It Right). Gildroy adds a brief chapter on vitamin/mineral supplements--pointing out that we probably don't know all the essential nutrients for man, and advising a supplement-free diet if possible, supplements ""if you need them."" (Throughout one finds evidence that Davis was right in her initially controversial findings on the roles of various vitamins--A and natural resistance, C and healing, etc.) There may be too much physiological detail for many readers; but those who agree with the basic premise (and Davis' considerable following) will find this an absolutely reliable source in a familiar style.