As recommended by the National Academies Committee, the advisory committee also will implement a “system science approach in informing the dietary guidelines,” Sarah Booth, Ph.D, chair, DGAC, explained during the committee’s second public meeting during the current review cycle. This includes implementing simulated diets or food pattern modeling analyses.
Prioritizing questions on optimal diet for children
The committee also prioritized questions about optimal diet and its impact on growth, body composition and risk of obesity in children.
Additionally, DGAC will consider the link between parental and caregiver feeding styles and dietary patterns “to make sure that we have the full range and consistency as we consider recommendations across the life stages,” explained Angela Odoms-Young, Ph.D, vice chair, DGAC.
The members also discussed a draft protocol to evaluate evidence on repeated exposure and food acceptance among children from birth to 12 years of age. Repeated exposure “refers to the number, duration and frequency of food offerings to promote liking and intake.”
Defining nutrient recommendations, particularly for low carbohydrate diets
DGAC highlighted the importance of the Dietary Reference Intakes (DRI) nutrient recommendations and its impact on the development of the dietary guidelines. While the DRI is established by the National Academies, federal working groups, including representatives from USDA, Department of Health and Human Services (HSS) and Health Canada, provide input. New DRI values for energy are now available and will inform the committee's work.
In response to public comments and committee discussions on defining low carbohydrate diets, the committee commissioned systematic reviews for subsequent DRI values for protein and carbohydrates, which will be completed through the HHS Agency for Healthcare Research and Quality.
Chris Taylor, Ph.D., DGAC member, explained that this review will “give us a better handle on definitions of low carbohydrate” and understand what “the nutritional implications [are] on spreading the calories out across other food categories.”
DGAC adds two subgroups and dietary assessment tool to refine protocols
Updates also were provided on several projects related to dietary guidelines.
One of them is the Healthy Eating Index (HEI), a tool that assesses how well a set of foods and beverages align with the dietary pattern recommendations in the dietary guidelines. The new version of the tool is expected to be published in September 2023. DGAC also introduced a new HEI for toddlers ages 12-23 months that reflects new guidance in the Dietary Guidelines for Americans.
The introduction of the Health Equity Working Group, which was formed to discuss how to incorporate principles of health equity across all the subcommittees, will inform each subcommittee through the lens of health equity.
“The Dietary Guidelines Advisory Committee was charged with ensuring that all of the scientific questions that would be reviewed through the health equity lens to ensure that the 2025 update of the dietary guidelines is relevant to people with diverse racial, ethnic, socio economic and cultural …to the greatest extent possible based on the information provided in the scientific literature and data,” added Sameera Talegawkar, Ph.D, DGAC member.
Given the committee's limited time and finite number of questions to address, DGAC also introduced the Meta Analysis Working Group, which intends to implement past dietary data analysis and refine protocols for the systematic review team.
Defining what’s in the food you eat, “not just what you eat”
DGAC’s draft protocol on food subgroups is based on corresponding nutrient profiles that use existing dietary data to reflect actual consumption patterns.
Taylor outlined these key subgroups as:
- Nutrient profiles which represent the projected nutrient intake expected from a particular food, such as vegetables, based on the vitamins, minerals, carbohydrates, fiber, and protein content.
- Item clusters which are the particular foods that make up each category (i.e. carrots, celery, and onions for the vegetable group).
- Nutrient-dense foods which DGAC identifies as the most nutrient-dense versions of a food that are equivalent to what is typically consumed, such as skim milk as a representative for whole milk. The nutrient dense representative foods limit added sugars, sodium, and saturated fat.
Taylor explained that “the revised nutrient profile item clusters are typically higher in energy and lower in nutrient density,” although, he mentioned there was a debate about whether to include less nutrient-dense foods high in added sugars, saturated fat and sodium in the nutrient profiles, but the current approach includes all foods.
Public comments, however, suggested “creating a revised nutrient profile using only higher nutrient-dense foods to create a tighter storyline around each food group.”
The goal, Taylor explained, is to create a nutrient profile that promotes healthy eating patterns while allowing for a broader selection of foods within each category. He added, “So it's the ‘what's in the food you eat’ and not just what food you eat.”
The full draft protocols will be posted on dietaryguidelines.gov at the end of May. Public comments are open for submission until the end of June and can be submitted here.