And every five years the American public largely ignores it.
Special interest groups, however, watch the guidelines closely and are speaking out. Just last week, nearly 50 speakers from industry and the science and health communities went to Washington to provide oral comments on the proposed guidelines for 2010, which will be released at the end of the year.
The proposed recommendation to reduce salt intake dramatically drew a statement from Morton Satin, Salt Institute vice president of science and research, that "no modern society consumes so little salt."
Dr. Richard Feinman, on behalf of the Nutrition and Metabolic Society, invited members of the federal Dietary Guidelines Advisory Committee to a debate on the guidelines' proposed decrease in saturated fat consumption, saying that carbohydrates eaten with saturated fats were the real problem. The Weston Price Foundation, which advocates the healthful properties of fat from pastured animals, also took issue.
A dietary supplements industry group called the Council for Responsible Nutrition objected to the proposed statement that "a daily multivitamin/mineral supplement does not offer health benefits to healthy Americans." The council said the committee's report implies "it's reasonable to allow people to live with nutrient inadequacies."
If the guidelines are largely ignored by the average American, why do health and industry groups care so much about influencing them?
"I think to a certain extent they are followed," said Weston Price Foundation President Sally Fallon, whose organization also supports the consumption of whole, rather than processed, foods. "Schools who get federal money and prisons are supposed to be following them for their menus."
Have questions about the new food guidelines? Many do. Reporter Monica Eng answers some of them at Trib Nation.
Dr. Robert Post, deputy director of the U.S. Department of Agriculture's Center for Nutrition Policy and Promotion, said all public comments are taken into consideration along with scientific reviews and lively debate within the committee's meetings.
He noted that last month the department debuted something called the Nutrition Evidence Library, a new online resource cataloging the latest science on nutritional matters and the ways the USDA interprets it to create policy.
But some observers still worry that the guidelines may be too influenced by industry concerns.
"I believe that by supporting low-fat products and grain products, rather than actual low-fat foods and whole grains like quinoa and teff, they are just trying to support the food industry," said Adele Hite, a University of North Carolina public health graduate student who represented the Committee for a Healthy Nation during last week's meeting.
The USDA started giving out nutritional advice more than 100 years ago with a table of food composition and dietary standards that later morphed into food shopping guides for various income levels. In 1992 the agency developed the food pyramid, an image in which horizontal bars represented food groups.
In 2005 the pyramid was given a new look (and renamed My Pyramid) in which the bars were replaced by vertical stripes that some argued made it hard to read at a glance.
"The new pyramid is not so much an information image as something to send people to the mypyramid.gov Web site," explained USDA spokesman John Webster.
"While making it, there was a concern that it was not specific enough," Webster said. "But as we added more information it started to look like a Christmas tree. Finally we said we can't continue to add more information and still make it meaningful, and so decided to put the information on the Web."
Congress mandates that a committee on the dietary guidelines convene every five years to review the latest science and state of the American diet to make adjustments, but the pyramid usually does not change as often. It will likely get another makeover in early 2011 as part of the national Let's Move campaign against childhood obesity.
The main changes proposed for the dietary guidelines include reducing daily sodium intake from 2,300 milligrams to 1,500 milligrams, reducing the percentage of saturated fat in the diet from 10 percent to 7 percent, reductions in foods with added sugars and an avoidance of artificial trans fats altogether. The report also highlighted the importance of vitamin D, calcium, potassium and dietary fiber, and it recommends eating 8 ounces of seafood a week.
Because most Americans already consume more sodium than was recommended in the last version of the guidelines, the new target of 1,500 milligrams is likely to pose formidable challenges to American consumers, not to mention food processors who rely on sodium as a flavor enhancer, preservative and binder.
Some experts acknowledge that although the proposed guidelines may force manufacturers to reformulate processed foods for schools and prisons that follow the standards, they may have little effect on what consumers eat at restaurants or at home.
"I think people ignore them when it comes to eating more fruits and vegetables and reducing refined sugars, but they will listen when they see the permission to eat six to 11 servings of grain per day," Fallon said.
The proposed 2010 guidelines are the first to acknowledge America's dire obesity epidemic and the roles environment and communication play in actually getting the public to follow the suggestions.
They cite "powerful influences that currently promote unhealthy consumer choices, behaviors and lifestyles" in our environment and call for cooperation with the Department of Health and Human Services to encourage improvements in areas including health, nutrition and physical education in schools; greater financial incentives to purchase, prepare and consume healthful food; more health-promoting foods and portions offered in restaurants and by manufacturers; and more exercise-friendly communities.
Among the questions the committee considered for this year's guidelines was how much and what kinds of fish consumption it could endorse given the latest research on mercury contamination.
Unlike the current food pyramid, the government's latest proposed advice takes into consideration the health threats posed by mercury, a toxic metal that taints certain types of fish and can trigger learning difficulties in children and neurological and heart problems in adults.
The proposed guidelines reflect a 2004 joint advisory from the Food and Drug Administration and Environmental Protection Agency that cautions young children, pregnant women, nursing mothers and women of childbearing age not to eat swordfish, shark, king mackerel and tilefish because of high mercury levels. It also advises those groups to consume no more than 12 ounces of fish a week, including no more than 6 ounces of canned albacore tuna.
An online version of the current food pyramid continues to recommend swordfish and tuna, four years after the Tribune first reported on the government's contradictory advice. The National Academy of Sciences has sharply criticized the government for not doing enough to advise consumers about which fish are safest to eat, a job that has fallen to nonprofit health groups.
Based on the government's own testing, Consumers Union, the publisher of Consumer Reports magazine, says the chances that any type of canned tuna will contain high levels of mercury are great enough that pregnant women should never eat it.
"You can get all of the benefits of fish and avoid the dangers of mercury by eating low-mercury fish," said Jean Halloran, the group's director of food policy initiatives. "It's been distressing to see the government isn't doing a better job helping women make smart choices."
The seafood industry has argued that advising women about high- and low-mercury types of fish would scare them away from eating seafood altogether. Yet a 2008 federal study found a decline in the number of women nationwide with high levels of the toxic metal in their bodies, even though those women were eating the same amount of seafood. The finding suggested that consumer advisories about mercury had started to work.