Why AOCS Wrote to USDA About a Factual Error in the Dietary Guidelines

On September 11, 2026, AOCS sent a letter to Shiela Corley, Acting Administrator of the USDA Food and Nutrition Administration (FNA), flagging a factual error in dietary fat guidance that FNA is now encouraging states and school food authorities to put into practice. It’s the kind of letter AOCS doesn’t write often, but it’s exactly the kind of issue we exist to weigh in on.

The context

The Dietary Guidelines for Americans, 2025-2030 tells readers to prioritize oils with essential fatty acids when cooking or adding fats to meals, and names olive oil as an example, adding that butter or beef tallow are other options.

That guidance is no longer just a recommendation sitting in a federal document. Through the Harvest to Hallways initiative, announced August 24, 2026, and the accompanying Pledge for Healthier School Meals, FNA is actively encouraging states and school food authorities to implement the 2025–2030 Guidelines right away. In practical terms, that means this specific sentence is now shaping which fats and oils get purchased and used in school kitchens across the country.

The error

Only two fatty acids are essential in human nutrition: linoleic acid and alpha-linolenic acid. The body can’t make either one, so both have to come from food. Olive oil’s dominant fatty acid, oleic acid, isn’t one of them; the body synthesizes it on its own.

Using current international compositional standards, corroborated by recent peer-reviewed measurement, the three fats named in the guidance (olive oil, butter, and beef tallow) turn out to be among the poorest sources of essential fatty acids among the fats commonly used in food service. Soybean, canola, safflower, sunflower, cottonseed, and corn oils all provide meaningfully more.

So a school food authority following that sentence as written would actually reduce the essential fatty acid content of the meals it serves. And if it reaches for butter or beef tallow, it would also raise saturated fat delivery, working against the same document’s own guidance that saturated fat should stay under 10 percent of daily calories.

This isn’t a matter of interpretation. The compositional data are well established and not in dispute.

What AOCS asked for, and offered

AOCS asked FNA to update the Child Nutrition Program materials within its own control (Harvest to Hallways resources, Pledge outreach, technical assistance memoranda, and state agency training) so that the recommendation to prioritize essential-fatty-acid-rich oils is backed by oils that actually are meaningful sources of linoleic and alpha-linolenic acid.

We also offered to help however would be useful:

• Compositional reference data and the analytical method citations behind them, for any fat or oil used in Child Nutrition Programs
• Technical review of draft guidance, training materials, or rulemaking language before it’s published
• A briefing for FNA staff on fatty acid composition and nomenclature as it applies to school food service

Why AOCS speaks up on something like this

AOCS is a scientific society devoted to the chemistry of fats, oils, lipids, and related materials. We publish the Official Methods and Recommended Practices of the AOCS, the analytical standards used worldwide by industry, government laboratories, and the Codex Alimentarius Commission to determine the composition of edible fats and oils. We don’t write on behalf of any commercial interest, and this letter doesn’t advocate for one oil over another commercially. Our concern is narrower than that, and entirely factual: guidance that’s meant to help people make healthier choices should reflect what the chemistry actually shows.

That’s also, in large part, why AOCS exists. When a federal document that will shape school meals nationwide contains a compositional error, we have both the expertise and the standing to say so, and to help fix it.

Read the full letter

Members can read AOCS’s complete letter to FNA, including the full data comparison and citations, here: AOCS Letter to FNA on Essential Fatty Acids (PDF).

We’ll keep members updated as this conversation with FNA develops. If you have questions about the science behind the letter, reach out to us at general@aocs.org.