The Dietary Guidelines for Americans are updated and issued every five years by the USDA and the Department of Health and Human Services, with the Dietary Guidelines Advisory Committee’s (DGAC) final meeting on the guidelines held on 15 December.
It is understand that the decision has been made on the grounds of sustainability, rather than nutrient value.
Barry Carpenter, president and chief executive of NAMI, said: "The committee’s removal of nutrient-dense lean meat from a healthy dietary pattern is stunning.
"The change was made behind closed doors during a lunch break at the final 15 December meeting. Actions made in haste behind closed doors are not rooted in science and do not make good public policy."
The Institute suggested the DGAC failed to recognise the nutritional value lean meat offers and "is ignoring the scientific evidence supporting its inclusion in the American diet".
It said that subcommittee data from the previous meeting on 7 November demonstrated strong and evidence that red and processed meats consumption was part of healthy dietary patterns, and called on the agencies for lean meat and poultry to be include as a component in guidelines.
"If the DGAC believed lean meat was not part of common characteristics of a healthy pattern, why was it included in the draft evidence conclusion through the morning of 15 December?," it asked.
"The Committee wrongly assumed that if production animal agriculture were eliminated, the food supply as a whole would be more sustainable," it added.
The Report of the 2015 DGAC will be submitted to the Secretaries of the Departments of Health and Human Services and Agriculture early this year.
After submission, a Federal Register notice will be published announcing the availability of the Report, a public comment period, and a date of a public meeting for providing comments to the Federal Government on the report.