Ms. Waldo leads off with a statement by the Committee on Nutrition of the American Heart Association which sets forth findings on the relation of diet to heart disease. Then follows an introductory discussion of cholesterol (it is not, like fat, a food but a fatty substance which clings to the arterial walls) and saturated, unsaturated, and polyunsaturated fat. There are tables, charts and research reports analyzing the effects of salt/cholesterol/fat in the diet which point to the fundamental raison: cut down on total fat calories, the larger portion consumed being of the unsaturated type. The going is a bit heavy but there are explicit guides; for example, in buying margarine make sure it contains liquid oil, polyunsaturated fats and is only partially hydrogenated -- read the label. Then on to the recipes, each one with calorie and fat counts listed per serving. Typically the dishes are vaguely heartland American, reliable and simply presented. And Waldo does her competent best within the restrictions: a little sherry in a souffle, an interesting egg white mayonnaise, and an omelet with 1 yolk, 2 whites. Firm.