JANE BRODY'S GOOD FOOD BOOK: Living the High Carbohydrate Way. Norton. 700 pp. $19.95.

IT IS extraordinarily difficult, even under experimental conditions, to compare one diet with another except during the growth period or when specific deficiencies exist or are produced. The classic deficiency syndromes -- starvation, beriberi, pellagra, scurvy and rickets -- have long been recognized; but only recently have we realized that diet and disease states can be causally related even when there is no known deficiency.

Some time during the 1940s the late Harold Ross, editor of The New Yorker and a sufferer both from peptic ulcer disease and the dietary privation this forced upon him, prevailed upon his gastroenterologist, Dr. Sara Jordan, to collaborate with Sheila Hibben in the production of a new kind of cook book: Good Food for Bad Stomachs (Doubleday, 1951). The year it appeared E. Virginia Dobbin and her coauthors published the first modern cook book, of which I am aware, designed to lower serum cholesterol levels, The Low Fat, Low Cholesterol Diet (Doubleday, 1951).

Neither book was intended to correct or prevent a deficiency; both presented the thesis that what one eats has health implications beyond the earlier, more limited view of nutrition; and both promised to make healthy meals more enjoyable. It is not that earlier books were oblivious to therapeutics. Quite the contrary -- in the 19th century, books on homemaking included instructions on a wide variety of subjects including home remedies and recipes. In early 20th century cook books, there were extensive sections on equipping a kitchen and on buying, preserving and serving food as well as catalogues of recipes. The broad general cook books were, presumably, attempts to instruct young brides in the several skills needed by a homemaker; and each aimed to be the only book she needed. After World War II, as cook book collecting became popular, the books became more specialized and narrow in scope, and many became nothing more than recipe collections.

It is from these ancestries that Jane Brody's Good Food Book springs. It is simultaneously a book on nutrition and weight loss; a "how to" equip a kitchen, shop for food, stock a larder, cook and eat out; and a recipe book. Brody properly stresses the current emphasis on exercise without which efforts at weight loss are almost surely doomed; and she reminds us that diets with generous amounts of complex carbohydrates and fibre are now believed to facilitate weight reduction and to offer protection against both heart disease and cancer. There are even little informational gems sure to delight trivia fans.

The nutritional caveats are presented in the first 200 pages. They are an accurate and understandable presentation of current dietary beliefs, and she seasons the data with a sprinkling of helpful hints and strategies for achieving the goals. Although we have read most of this before in her New York Times articles and in Jane Brody's Nutrition Book, the repetition is necessary -- as I can attest from having to repeat the few principles time after time to my patients before they are finally understood, absorbed and available for use by those who want better nutrition but don't know how to achieve it.

Brody then proceeds to a highly professional exposition of how to equip a kitchen, stock a larder and perform basic cooking techniques. It is clear that she does not accept as necessarily correct a way of performing a task merely because that is the way it has always been done. Rather, she examines critically what she is doing. The result is that even experienced cooks will find useful tips in this section.

Finally, there is an eclectic collection of abou 350 recipes. The range, from homely to epicurean, is so large that they cannot be reviewed en masse except to point out that they provide proof that the principles espoused can be translated into good food.

The book would have been even more valuable, in my opinion, if the cholesterol and fat content (especially saturated fat) of each recipe -- or better yet of each ingredient -- had been stated. Such information would have allowed readers to know what they were eating and would have guided them in the use of recipes from other sources. Brody's explanation that the available figures may in some instances be inaccurate is undoubtedly correct; but she herself points out that we are here now and need to do now the best for ourselves that we can. This has to be based on the most reliable, currently available knowledge; we cannot, as she says, "afford to wait for every i to be dotted and t to be crossed."

Despite this objection I regard the book as an important achievement. It is a compilation and digestion of an enormous amount of technical literature. Brody has taken the writings of physicians, biochemists and nutritionists and presented them in popular accents to a lay public that does not have easy access to the original writings, that cannot readily understand them, and would be hard put to resolve the frequent, conflicting claims. Her voice has been more effective in carrying our message to large groups of people than have ours in the medical profession. She has sounded the alarm in her articles, in Jane Brody's Nutrition Book, and now in Jane Brody's Good Food Book; and she has clearly and effectively disseminated the medical profession's recommendations. I hope you are listening.