Anyone who feels queasy trying to sort out the torrent of opposing ""expert"" opinions on nutrition (see Drs. Newbold and McQueen-Williams above, and a hundred others) will give thanks for this little book of clarification. Wordsworth is not pandering another miracle regimen; she aims only to ""summarize the many rival theories."" The ""diet reformers"" fall into two major sects: those who urge high protein intake (per the Gaylord Hauser-Adelle Davis school) and those--chiefly European--who extol the virtues of various degrees of vegetarianism. Both groups, she notes, are prone to half-truths and exaggerations. Take the word ""pure""--the assumption is that pure equals good. But as Wordsworth points out, two of the purest things in the kitchen are white sugar and table salt, and neither is good for you. Similarly, she examines the two scapegoats of the reformers, ""poisons"" and ""deficiencies""--both products of refined processed foodstuffs and both freely blamed for everything from irritability to cancer. Honey, kelp, yogurt, and other wonder foods are evaluated critically--not unsympathetically--and the health food store's ""bottled side of the business"" gets its due. Clear, scrupulously fair, this is a much-needed guide for the perplexed.