Once every five years, the federal government goes to great lengths to update its recommendations for how Americans should eat. In fact, Congress mandates that the Dietary Guidelines for Americans (DGA) be based on the most current science available. Yet over the years, the DGA process has been wrought with politics, which should come as no surprise. With each cycle, we gather to witness just how strongly the food industry has managed to exert its influence.

Last week's release of the 2010 version was no different. Like most versions before it, it inspired plenty of spin and criticism. But really, what does it matter?

The time has come to ask, are dietary guidelines just another charade, a waste of taxpayer dollars? Who even pays attention, except for a bunch of dietitians, food industry lobbyists, the media (for about a minute), and a few policy wonks like me and my fellow Grist contributor Tom Laskawy? The general public barely notices; and after the initial media blitz, it's back to business as usual for the next five years.

Now, the guidelines do play an important role in setting nutrition standards for the federal food assistance programs, and I certainly don't mean to belittle this important purpose. But given the huge disconnect between actual science (which the DGA is supposed to be based on) and what comes out the other end, why do we keep bothering to engage in this hopeless charade?

While the 2005 version's take-away message seemed to be that Americans needed to eat more whole grains, this time, the media fixated on the DGA's warning to eat less salt. (It seems we can only handle one basic nutrition concept every five years.) But as I told Andy Bellatti for his blog post on this topic, such advice is doomed to failure because of our toxic food environment. Such reductionist messages also provide industry an opportunity to retool its junk food to downplay the "bad ingredient" du jour:

Telling people to cut back on salt in the current food environment is like telling fish not to die in a polluted stream. Just like we have restrictions on pollutants in water and air, we need regulations that restrict salt in food. But of course, the food industry would go ballistic over that idea. Big Food is happy to have Uncle Sam keep doling out meaningless advice. And, we are likely to see more "low-salt" junk food soon, just as we saw "whole grain" Reese's Puffs cereal in 2005. That worked so well.

Things did get a little better this time around. Veteran food politics maven Marion Nestle declared herself "in shock" at such obvious DGA statements as, "avoid oversized portions," "drink water instead of sugary drinks," and the most straightforward and useful piece of advice, "make half your plate fruits and vegetables." But somehow even these no-brainers didn't make it in the government's 90-page "policy document," as Nestle explains.

Despite these modest improvements, most messages in the 2010 DGA remain lame. While some experts are understandably pleased that the government is finally telling Americans to "eat less," I doubt that such vague advice will have enough tangible meaning to be effective, especially with the food industry constantly telling people to "eat more."

I went back to read my take on the 2005 update and realized that very little has actually changed. In an op-ed piece published in the San Francisco Chronicle, "Why Uncle Sam won't tell you what not to eat," I concluded:

Americans need is to be told outright: Stop drinking so much Coke. People don't think in terms of ingredients. Most consumers don't even buy ingredients anymore because they don't cook. We think in terms of packaged-food brand names and fast-food menu items. Imagine dietary guidelines that said: Stop eating Big Macs, Doritos and Oreos. Those are recommendations most Americans could understand, but not ones we are likely to hear. Until people are told the entire truth, instead of meaningless messages such as "eat less," the nation's health will continue to suffer.