By Jessica DiNapoli and Emma Rumney

NEW YORK, June 11 (Reuters) - The U.S. Dietary Guidelines for Americans, which influence school lunches, medical advice and nutrition standards, are expected to be released as soon as June, two sources familiar with the matter said.

The Trump administration is accelerating the timeline to impact meals served in the upcoming school year, starting later this summer, one of the sources said. However, it is already late for many school districts to adjust items they purchase, said Diane Pratt-Heavner, the director of media relations for the School Nutrition Association.

The upcoming dietary guidelines are still being developed and nothing has been decided, a third source familiar with the matter said, adding they were expected to address saturated fat, found mainly in meat and certain oils, and ultra-processed food. Recommendations on drinking alcohol are not slated to dramatically change, the source said.

The guidelines will likely modify suggestions related to dairy consumption, according to an industry source. Currently, the dietary guidelines recommend low and non-fat dairy, but the new ones may include whole fat dairy, the source said.

The sources requested anonymity because they were not authorized to speak to the media.

Health and Human Services and the U.S. Department of Agriculture publish the guidelines jointly every five years. Former President Joe Biden's administration began the process of drafting the guidelines.

The agencies did not immediately respond to a request for comment.

The guidelines are the basis for school nutrition standards, which are set by the USDA.

Asked during a Tuesday press conference if the revised guidelines would include any changes to limits on saturated fats, Agriculture Secretary Brooke Rollins declined to provide details.

"We're looking at everything right now. I don't want to make news today, but you'll be hearing a lot more on this in the coming weeks," she said, adding that her goal was to have the full guidelines out in the next month or two.

U.S. Health Secretary Robert F. Kennedy Jr. said last month that the guidelines would be four pages long, published by August and emphasize eating "whole food."

A report commissioned by Kennedy last month said the guidelines were compromised by corporate interests, such as the meat and sugar industries.

The report, named after the Make America Healthy Again social movement linked with Kennedy, also said that the current guidelines' recommendation to reduce saturated fat and sodium was problematic, and should instead focus on minimally processed food.

The current dietary guidelines recommend limiting saturated fat to less than 10% of total calories consumed daily, and do not address ultra-processed food. The definition of ultra-processed food is hotly debated by the food industry while the report describes it as industrially manufactured products.

The guidelines recommend limiting consumption of alcoholic beverages to one a day for women and two for men, or not drinking.

The U.S. Department of Agriculture is required to set standards for school meals that align with the dietary guidelines. The guidelines also impact Supplemental Nutrition Assistance Program $(SNAP)$, an anti-hunger program. Doctors, nutritionists and dieticians also rely on them when advising patients.

School districts may struggle to meet the recommendations of the new dietary guidelines by the time school starts. Most school districts placed orders for fall 2025 menus at the beginning of the year, Pratt-Heavner said.

"Meeting mandatory changes to the nutrition standards or meal pattern would be extremely difficult given these procurement issues, but the administration could offer flexibility," such as allowing schools to offer whole milk, Pratt-Heavner said. Schools may now only offer fat-free and low-fat milk.

(Reporting by Jessica DiNapoli in New York, Emma Rumney in London, Renee Hickman in Chicago and Leah Douglas in Washington; Editing by Caroline Humer and Jacqueline Wong)

((Jessica.DiNapoli@thomsonreuters.com; 845-591-4428; Reuters Messaging: Twitter: @jessicadinapoli))