The Obama administration’s campaign for healthy diets is heading for a conflict with a well-funded industry as a panel of scientists is poised to tell Americans to eat less sugar.

The Dietary Guidelines Advisory Committee will suggest this month limiting sugars to no more than 10 percent of all calories, down from the average 13 percent now consumed by U.S. adults, as part of a once-every-five year overhaul of a consumer guide. It would be the panel’s first explicit target for sugar in the diet.

The administration already has landed in food fights over first lady Michelle Obama’s “Let’s Move!” anti-obesity initiative, which encourages healthy eating. And Republicans have said Obama-backed nutrition rules rob school districts of flexibility.

Food industry groups are howling that the dietary panel’s scientists overreached and should be reined in.

“People who hate the Obamas will add this in,” said Marion Nestle, a nutrition professor at New York University and a dietary advisory committee member in 1994-95. “The industry will do what it’s always done: You attack the science, you attack the individuals who are making statements on it, and you go behind the scenes and lobby.”

Groceries, Lunches

Suggestions by the nonpartisan panel of academics and scientists can have far-reaching effects. The nutrition guidelines help shape school lunch menus and the $6 billion a year Women, Infants and Children program, which serves more than 8 million Americans who buy groceries from retailers including Wal-Mart Stores Inc. and Kroger Co. They also are the basis for the dinner-plate icon that replaced the food pyramid widely used in public-education campaigns about a healthy diet.

The panel hasn’t published its recommendations, and members declined to comment in advance of an announcement. Documents and public testimony, however, reveal the outlines of its findings.

Committee members also are suggesting adding detailed sugar information on Food and Drug Administration nutrition labels, limiting the use of food stamps to healthy choices and endorsing sustainable agricultural practices. They are also encouraging the government to take steps to discourage consumption of sodium and red meat, as well as issuing its first recommendations to boost sustainable agriculture.

USDA, HHS

The committee decided to submit recommendations from its final meeting on Dec. 15 as the basis of its report, Kellie Casavale, a nutrition adviser in the Department of Health and Human Services who is working for the panel, said at the session. Any changes now would be minor, she said.

HHS, which is in charge of writing the guidelines, and the U.S. Department of Agriculture jointly appoint the committee, then act on its recommendations after considering public comment. Final guidelines will be released by the end of this year.

The Obamas “have made it a priority to ensure that Americans have access to the information they need to make smart choices about health and nutrition,” USDA undersecretary Kevin Concannon, said at the first meeting of the panel in June 2013, while noting the group is an advisory body only.

In comments to the panel, the Sugar Association, a trade group of farmers and refiners including Domino Sugar-maker American Sugar Refining Inc., said it’s “mystified” by some of the work, and called “added sugars” a misleading term.

Science Based

Recommendations should be based “on the preponderance of scientific information,” the group said in a Jan. 7 statement.

Drinking sugary beverages is tied by scientists to high obesity rates, and local governments such as New York City have deemed sugars a public-health threat. The U.S. obesity rate nearly tripled from the 1960s to 2010 as Americans consumed more sugar.

Efforts to encourage better diets, from raising taxes on sodas to imposing limits on supersize beverages -- backed by former New York City Mayor Michael Bloomberg, owner of Bloomberg News parent Bloomberg LP -- have failed at ballot boxes and in courtrooms.

One exception: Berkeley, California, voters overwhelmingly approved he nation’s first tax on sodas last year.

A recommendation by the panel to limit sugar consumption probably will be diluted before becoming final later this year, nutrition advocates say. The soda and meat industries already are poring over the diet committee’s work, and the American Beverage Association said in comments that panelists “appeared to be biased toward pre-determined outcomes.”

Economic Incentives

The panel also recommended the government consider economic incentives and disincentives as a way to encourage better eating. To industry, that sounds like soda taxes, which drew a rebuke from the American Beverage Association: “Taxation of food is not within the purview” of the committee, according to comments filed with the panel. The association represents Coca- Cola Co. and other soda producers.

The beverage association, which declined requests for an interview, has spent $37.2 million since 2003 on various issues, according to a decade of data from the Center for Responsive Politics, which tracks spending to influence policy.

The committee’s discussions on possible health risks from eating too much meat and sodium-rich foods also drew criticism.

The North American Meat Institute worries that panel’s warning of dangers from saturated fats may kill references to “lean meat” being part of a healthy diet. The group said such a conclusion is contrary to science. The trade group shared its concerns with lawmakers, said spokeswoman Janet Riley, without providing specifics.

Sustainability Initiative

The panel’s sustainability initiative included endorsing plant-based diets and urging more consumption of farm-raised fish to alleviate overfishing. The idea has sparked action in Congress: An appropriations bill passed last month includes a non-binding provision telling the guideline agencies -- the USDA and HHS -- to “only include nutrition and dietary information.”

Historically, committee efforts to provide clear direction have been watered down after lobbying, Nestle said.

In the first dietary guidelines, in 1980, guidance on sugar was four words long: Avoid too much sugar. That’s been progressively obscured in subsequent guidelines. Implicitly, the 10 percent limit has been part of government recommendations, but direct language has been avoided, she said.

This time around, greater public awareness of proper diet, in part spurred by the Obamas, may make it harder to bend them to industry goals, Nestle said. The guidelines are only as effective as the political will to defend them, said Michael Jacobson, executive director of the Center for Science in the Public Interest, a consumer advocacy group in Washington.

“The administration will be able to back up the science,” he said. Once the agencies publish the guidelines, he said “the sugar and meat industries can run to Congress, and Congress can limit the impact of the guidelines.

‘‘I don’t know how much they’ll be able to get away with.”