IDFA asking DGAC: Don’t ignore scientifically valid studies on dairy and milkfat
Asking 2025 Dietary Guidelines Advisory Committee to formulate plan based on the scienceThe International Dairy Foods Association (IDFA) submitted comments on Friday on the protocols to examine the scientific questions that will be addressed by the 2025 Dietary Guidelines Advisory Committee (DGAC). The letter was submitted by Dr. Joseph Scimeca, IDFA's Senior Vice President of Regulatory and Scientific Affairs and noted that "ensuring that all the relevant and valid scientific studies are included in the systematic reviews will lead to dietary recommendations based on the preponderance of the best available nutrition science."
In submitting comments, IDFA was responding to the 2025 DGAC’s request for feedback as it reviews the body of scientific evidence on nutrition and health necessary to formulate a credible and reliable Dietary Guidelines for Americans report at the end of 2024. IDFA believes that a credible, reliable DGAC report will put dairy foods at the center of healthy dietary patterns for people of all ages and backgrounds.
IDFA’s comments to the DGAC included the following:
- Do not ignore scientifically valid studies: Ensuring that all the relevant and valid scientific studies are included in the systematic reviews will lead to dietary recommendations based on the preponderance of the best available nutrition science.
- Release the protocol on specific food sources of saturated fat: IDFA is pleased that one of the scientific questions slated for systematic review relates to specific food sources of saturated fat. However, as of June 30, 2023, the proposed protocol for addressing this question is not yet available for public review. We urge the DGAC to release the protocol as soon as it is available and to allow for a similar amount of time to comment as provided for the other protocols. In order to properly answer the proposed question, the DGAC will likely need to review single food studies and include them in the protocol. The exclusion of single food studies was a primary reason that many studies on saturated fat in dairy were previously excluded. Including these studies will permit the 2025 DGAC to review the entire body of science exploring the relationship between dairy foods at all fat levels and health outcomes.
- Include consumption of lactose-free and low-lactose milk: We urge the protocol to specifically include consumption of lactose-free and low-lactose milk as criteria for both intervention/exposure and as a comparator in studies that will be included in the systematic review. Including lactose-free and low-lactose milk is important to address issues of nutrition security and equity.
- Not all processed foods are equal: Studies to be included under this protocol must clearly describe the eating pattern and consumption behavior, particularly the specific foods, the methods of processing (if any) and amounts consumed. A major limitation of some current food processing classification systems is that they group nutrient-dense foods, such as yogurt or whole wheat bread, as Ultra-Processed Foods (UPF), without regard for the beneficial effect of the food on health outcomes. Many of these foods provide essential nutrients to eating patterns and contribute to better health outcomes.
- Do not exclude meta-analyses: All DGAC protocols currently exclude meta-analyses from inclusion in the systematic reviews. While meta-analyses do use data from previously published studies, additional analysis is conducted as part of the process that may be a useful contribution to a systematic review. This is particularly helpful by pooling data that can permit more precise analysis of health outcomes. If there is concern about the strength or bias of individual meta-analyses, these concerns should be addressed in the same manner as for other study designs. A properly conducted meta-analysis will exclude those studies that fail to satisfy proper design criteria. If the DGAC decides to exclude meta-analyses from the systematic reviews, it will be important to ensure that the individual studies that are part of the excluded meta-analyses and which are valid and robust, are considered for inclusion in the DGAC systematic review.
The DGAC is appointed by the Departments of Health and Human Services (HHS) and Agriculture (USDA) and consists of 20 nationally recognized nutrition and public health university experts. The Committee is tasked with reviewing the current body of nutrition science on specific topics and questions and developing a scientific report that includes its independent, science-based advice for HHS and USDA to consider. The Committee’s review, along with public comments on its scientific report and agency input, will help inform HHS and USDA as they develop the Dietary Guidelines for Americans, 2025-2030.
To read IDFA’s full comments to the DGAC submitted on June 30, 2023, click here.