Whether you found the food pyramid created by the U.S. Department of Agriculture in 1992 beneficial or not, it was at least simple to use. The familiar triangular nutrition guide suggested how much of each food category—grains, dairy products, fruits and vegetables, meats and fats, oils and sweets—one should eat every day.

But in my opinion, the USDA’s 2005 replacement, MyPyramid, is a disaster. The process the agriculture agency employed to replace the 1992 food pyramid (left) has been kept secret. It remains a mystery, for example, just how the department came up with a design for a new food guide that emphasizes physical activity but is devoid of food (right). According to the USDA staff, people should keep physically active, eat in moderation, make personalized food choices, eat a variety of foods in the recommended number of servings, and pursue gradual dietary improvement. The color and width of the vertical bands of MyPyramid are meant to denote food groups and servings, but the only way to know this in detail is to log on to a computer. Users must go to www.pyramid.gov and type in gender, age and activity level to obtain a “personalized” dietary plan at one of a dozen calorie levels.

People who seek advice from this site, and millions have, find diet plans notable for the large amounts of food they seem to recommend and for the virtual absence of appeals to “eat less” or to “avoid” certain foods. Critics, not surprisingly, discern the strong influence of food industry lobbyists here. I myself, for example, am expected to consume four cups of fruits and vegetables, six ounces of grains, five ounces of meat and, of course, three cups of milk a day, along with a couple of hundred “discretionary calories” that I can spend on junk foods. For all its flaws, the 1992 pyramid was easier to understand and use.

What MyPyramid really lacks is any notion of a hierarchical ranking of the items in a single food group in terms of nutritional desirability. The preliminary design of MyPyramid in 2004 looked much like the final version with one critical exception: it illustrated a hierarchy of desirable food choices. The grain band, for instance, placed whole-grain bread at the bottom (a positive ranking), pasta about halfway up (a middle rank) and cinnamon buns at the top (“eat less”). In the final version, the USDA eliminated all traces of hierarchy, presumably because food companies do not want federal agencies to advise eating less of their products, useful as such recommendations might be to an overweight public. —M.N.