Trying to get Americans to eat a healthy diet is a frustrating business. Even the best- designed public-health campaigns cannot seem to compete with the tempting flavors of the snack-food and fast-food industries and their fat-and sugar-laden products. The results are apparent on a walk down any American street--more than 60% of Americans are overweight, and a full quarter of them are overweight to the point of obesity.

Now, health advocates say, an ill-conceived redesign has taken one of the more successful public-health campaigns--the Food Guide Pyramid--and rendered it confusing to the point of uselessness. Some of these critics worry that America’ s Department of Agriculture caved in to pressure from parts of the food industry anxious to protect their products.

The Food Guide Pyramid was a graphic which emphasizes that a healthy diet is built on a base of grains, vegetables and fruits, followed by ever-decreasing amounts of dairy products, meat, sweets and oils. The agriculture department launched the pyramid in 1992 to replace its previous program, which was centered on the idea of four basic food groups. The" Basic Four" campaign showed a plate divided into quarters, and seemed to imply that meat and dairy products should make up half of a healthy diet, with grains ,fruits and vegetables making up the other half. It was replaced only over the strenuous objections of the meat and dairy industries.

The old pyramid was undoubtedly imperfect. It failed to distinguish between a doughnut and a whole-grain roll, or a hamburger and a skinless chicken breast, and it did not make clear exactly how much of each foodstuff to eat. It did, however, manage to convey the basic idea of proper proportions in an easily understandable way. The new pyramid, called" My Pyramid", abandons the effort to provide this information. Instead, it has been simplified to a mere logo. The food groups are replaced with unlabelled, multi-colored vertical stripes which, in some versions, rise out of a cartoon jumble of foods that look like the aftermath of a riot at a grocery store. Anyone who wants to see how this translates into a healthy diet is invited to go to a website, put in their age, sex and activity level, and get a custom-designed pyramid, complete with healthy food choices and suggested portion sizes. This is fine for those who are motivated, but might prove too much effort for those who most need such information.

Admittedly, the designers of the new pyramid had a tough job to do. They were supposed to condense the advice in the 84-page United States’ Dietary Guidelines into a simple, meaningful graphic suitable for printing on the back of a cereal box. And they had to do this in the face of pressure from dozens of special interest groups--from the country’ s Potato Board, which thought potatoes would look nice in the picture, to the Mmond Board of California, which felt the same way about almonds. Even the National Watermelon Promotion Board and the California Avocado Commission were eager to see their products recognized.

Nevertheless ,many health advocates believe the new graphic is a missed opportunity. Mthough officials insist industry pressure had nothing to do with the eventual design, some critics suspect that political influence was at work. On the other hand, it is not clear how much good even the best graphic could do. Surveys found that 80% of Americans recognized the old Food Guide Pyramid--a big success in the world of public-health campaigns. Yet only 16% followed its advice.

The phrase "caved in" ( paragraph 2) most probably means（）

A. yielded

B.entered

C. promised

D. criticized