Every five years the federal departments of Agriculture and the Health and Human Services jointly release a set of recommendations for a healthy diet, similar to what any reasonable parent might suggest: Limit salt and sugar. Eat more veggies, and, for heaven’s sake, don’t supersize the burger and fries.

Yet Americans routinely ignore the recommendations, snarf up too much and too many of the wrong foods, and get fatter. So why is the arrival of yet another set of dietary guidelines worth noting?

First, the guidelines suggest a 10 percent cap on the calories that come from sugar added to foods (as in sweetened sodas, not juice), a much stricter limit than in previous versions, and recommend that males consume less protein derived from animals — not just red meat. These recommendations are meaningful because, despite the title, the dietary guidelines help determine what’s served in federal food assistance and school meal programs that serve millions of Americans.

Second, and perhaps more important, is that for the first time since the recommendations began in 1980, the feds have gone farther than just making a list of the elements of a healthy diet. This round, the nutrition panel took a broader look at the patterns of food consumption globally and said that Mediterranean and vegetarian diets were good options.

An earlier version of the guidelines released in February went further, calling for new taxes on sodas to reduce sugar consumption. It also broke a political taboo by advocating a diet with less red meat. Most unforgivable, at least to some members of Congress, was that the panel based its recommendations in part on how the production of various types of food affected the environment.

In California, where vegan cuisine is more or less mainstream, such suggestions may seem mild. In the U.S. Capitol, they were akin to declaring war on agribusinesses and their powerful lobbies. The beef industry took particular issue with the draft guidelines, saying that there was no scientific basis for suggesting that eating more plants and less meat would improve health.

The heads of the two agencies, Agriculture Secretary Tom Vilsack and Health and Human Services Secretary Sylvia Mathews Burwell, agreed that the dietary guidelines were not the appropriate place to discuss the larger questions about sustainability, and the new recommendations reflect that. While it might have been the wrong venue, however, the long-term impact of food production on the environment is an important topic that Congress must find a way to address.

One thing lawmakers did was fund a peer-reviewed study by the National Academy of Medicine of the science behind the dietary guidelines. The added research can only improve the next recommendations, but it’s likely to leave unanswered what may be the most important question about the guidelines: Why don’t more people follow them?

— The Los Angeles Times Jan. 8