Dietary Guidelines for Americans: Key Takeaways from the Fourth Meeting
The fourth meeting of the Dietary Guidelines for Americans Advisory Committee (DGAC) was held in Houston, Texas on January 23rd and 24th, 2020. The idea was to get out of the Washington D.C. area and offer those living outside the “beltway” an opportunity to be more involved in the Dietary Guidelines process.
Variety of Food Groups
Quick Review
Every five years a group of volunteer experts in the field of nutrition gather to review and update the Dietary Guidelines for Americans (DGAs) to reflect the latest science. The committee considers all earlier research and recommendations and reviews new material to update the guidelines to the best evidence-based recommendations available. The 2020-2025 guidelines will include recommendations for both a general population and specific populations with the addition of new subcommittees, such as the Birth through 24 Months subcommittee and the Pregnancy and Lactation subcommittee. The topics and questions were pre- determined by the two government agencies that spearhead the creation of the guidelines, the United States Department of Agriculture (USDA) and the United States Department of Health and Human Services (HHS). The DGAs are aiming to incorporate a life stage approach across their recommendations.
Past Meetings
The first, second and third DGAC meetings occurred in March, July, and October 2019, respectively. The first opportunity for public comments occurred during the July meeting and there were several common themes from commenters including low-carbohydrate diets, racial bias, climate change, plant-based diets, and reasons why industry involvement should be limited in the creation of the guidelines along. Look here for more detailed explanations on the second and third meetings: July Session and October Session.
Key Takeaways
The fourth meeting in Houston presented a lot of information and some possible answers to the pre-determined research questions. It was also the public’s second and final opportunity speak directly to the DGAC. Although the committee will be accepting written comments until their work is complete, the committee leadership urged individuals and groups to submit written comments addressing the new and updated protocols that have been discussed so far by Friday, February 7th, 2020. Every subcommittee offered some draft conclusions and updates to the topics and questions they are examining. Only one subcommittee reported that their review and work was complete. The remaining draft conclusions for topics and questions for the other subcommittees are expected to be reported on during the March 2020 meeting.
Birth to 24 Months Subcommittee
The Birth to 24 months subcommittee had a lot of ground to cover, specifically because this is the first time the DGAs will provide recommendations for this population. The subcommittee was able to provide draft conclusions for some of their questions, but they stated that there was insufficient research to draw conclusions for many of their topics and questions. During the fourth meeting the subcommittee reported on the relationship between exclusivity and duration of human milk (breastfeeding) and infant formula and several health outcomes including micronutrient status, food allergies and atopic allergic diseases, and long term health outcomes such as cardiovascular disease and diabetes. The subcommittee also looked at the role of complementary feeding and those outcomes as well.
Although many draft conclusion statements stated that there was insufficient, no, or limited evidence based on the research, there were a few notable correlations:
The subcommittee reported that there is moderate evidence to suggest that there is an associated higher risk of childhood asthma with infant formula compared to human milk.
The subcommittee reported that there is moderate evidence to suggest that a shorter duration of being fed human milk v. a longer duration of being fed human milk is associated with a higher risk of Type 1 diabetes.
The subcommittee reported that there is strong evidence to introduce peanuts in the first year of life to reduce the risk of food allergy to peanuts.
The subcommittee reported that there is moderate evidence to introduce eggs in the first year of life to reduce the risk of food allergy to eggs.
Baby Bottle Feeding
Pregnancy and Lactation Subcommittee
The Pregnancy and Lactation subcommittee’s goals are to look at specific nutrients and determine how they may impact a mother’s health and the baby’s development. The subcommittee experienced similar challenges as the Birth to 24 months subcommittee, limited, no, or insufficient evidence to answer their topics and questions. During the fourth meeting, they examined topics related to nutrients and fortified foods and dietary patterns.
Although many draft conclusion statements stated that there was insufficient, no, or limited evidence based on the research, there were a few notable correlations:
The subcommittee reported that there is moderate evidence to suggest higher levels of folic acid supplementation during pregnancy does not affect the risk of hypertensive disorders during pregnancy among women at low-risk.
The subcommittee reported that there is strong evidence to suggest folic acid supplementation before and/or during pregnancy is positively associated with folate status.
The subcommittee reported that a healthier diet was associated with lower risk of preterm birth and spontaneous preterm birth, but they noted that this was examined using a healthy, Caucasian population with access to healthcare.
Pregnant Woman
Dietary Fats and Seafood Subcommittee
During this meeting, the Dietary Fats and Seafood subcommittee focused on their draft conclusions and research focused on seafood. Like the Birth to 24 months subcommittee, this is a new subcommittee for the DGAs, although seafood has been included in past guidelines as a general food group. The subcommittee reported out on seafood consumption during pregnancy and lactation and its impact on neurocognitive outcomes, as well as childhood and adolescence and its impact on neurocognitive outcomes and cardiovascular disease.
Although many draft conclusion statements stated that there was insufficient, no, or limited evidence based on the research, there were a few notable correlations:
The subcommittee reported that there was moderate evidence to suggest seafood intake during pregnancy is associated with improvements in cognitive development in the child.
The subcommittee reported that there was moderate evidence to suggest seafood intake during pregnancy is associated with improvements in language and communication development in the child.
The subcommittee reported that there was moderate evidence to suggest seafood intake during childhood and adolescence does not have detrimental impact on cognitive development or on language and communication development.
Plate of Seafood
Beverages and Added Sugars Subcommittee
The Beverages and Added Sugars subcommittee’s goal is to look at beverage and added sugar intake and the impact on health across many life stages including pregnancy, childhood, adolescence, and adulthood. The first thing this subcommittee had to do was to break out the beverages by category and determine where beverages like kefir or sports drink would be. Unfortunately, all the draft conclusions presented by this subcommittee included insufficient, no, or limited evidence, but I don’t expect that to be the case for the next meeting. During the fifth meeting, the subcommittee will be reporting on added sugars and health outcomes as well as alcohol and health outcomes. These outcomes include cardiovascular disease, type 2 diabetes, growth, size, body composition, and risk of overweight obesity.
Beverages
Data Analysis and Food Pattern Modeling Cross-Cutting Working Group
If there was a prize for longest presentation or review of the most data, this subcommittee would receive it. The goal of this subcommittee is less focused on specific nutrients or foods and instead, they are examining how and what Americans are eating. Spoiler alert- it’s not great. The subcommittee used NHANES (National Health and Nutrition Examination Survey) and the Healthy Eating Index (HEI), NHANES is a national survey conducted yearly in multiple locations to get a picture of the nation’s nutritional and health status. Our national survey is one of the best in the world, and multiple nations have modeled similar studies off our approach. The HEI is a measure of diet quality against the current 2015 – 2020 DGAs. The average American diet scores a 59 out of 100 on the HEI. Although average diet quality has slightly improved over the last 10 years, this score of 59 indicates that diet quality is not consistent with recommendations from the current DGAs. The subcommittee was sure to note that much of this data is self-reported.
The subcommittee reported several interesting conclusions regarding how Americans are currently eating which provides a LOT of room for improvement:
Food and beverages consumed via mixed dishes, burgers and sandwiches, snack and sweets, and sugar-sweetened beverages contributed 50-60% of total energy intake.
Calories from total beverage intake account for approximately 15-18% of total energy intake for Americans ages 2 and older.
Across the life stage, diet quality is better among young children and older adults.
Nutrition related chronic health conditions are common across every life stage of the US population.
These chronic health conditions have become more prevalent over time and older populations, certain race-ethnicity groups and those with a lower income are disproportionately affected.
Certain nutrients such as sodium, saturated fat, and added sugars are overconsumed by 5% or more of the population and certain nutrients such as Vitamin D, Calcium, Potassium, and dietary fiber are under consumed.
The subcommittee also mentioned that there are certain nutrients among specific population groups that are under consumed, such as protein in adolescence and older females and Vitamin B12 in older adults.
Data Models
Dietary Patterns Subcommittee
The Dietary Patterns subcommittee is examining how eating patterns may be associated with various health outcomes. For this meeting, the dietary patterns subcommittee looked at whether choosing our foods based on a specific meal pattern had a beneficial effect on all-cause mortality, and their answer is…well kind of, it depends and possibly. The subcommittee’s findings mainly echoed what is in the 2015- 2020 Dietary Guidelines, and there were several conclusions presented by the subcommittee specific to adults and older adults:
Dietary patterns emphasizing the consumption of vegetables, legumes, fruits, whole grains, nuts, lean meats, fish, poultry and unsaturated fats or specifically olive oil have beneficial effects.
There may be protective effects with decreased intake of red or processed meats.
Commonly known dietary patterns such as “Mediterranean”, “Dietary Approaches to Stop Hypertension (DASH)”, and “plant-based” diets had a positive association with all-cause mortality, meaning higher adherence to these types of dietary patterns were generally protective against all-cause mortality.
Healthy Dietary Pattern
Frequency of Eating Subcommittee
The Frequency of Eating subcommittee and this topic is new for the DGAs. So far, the broader DGAC committee has looked at what nutrients we eat, what food categories we are eating, and what patterns we are eating, so that brings us to the question about how often we eat? This subcommittee was careful to explain that they are specifically looking at the frequency in which we eat, and they uncoupled that from the timing in which we eat. Unfortunately, the research was very very limited for this group once they were only looking at frequency of eating. Of the small amount of available research, there was also a large lack of racial and ethnicity representation, meaning it was very difficult to generalize this information for an entire population as diverse as the United States. The draft conclusion statements reported insufficient, limited or no evidence. Although this subcommittee reported that their work was complete, based on the questions from other DGAC members, I think they may be headed back to the drawing board to address these topics in more detail or to include other topics and questions like intermittent fasting.
People Eating a Meal Together
What Did the Public Have to Say?
Dietary guidelines influence a lot of policy decisions across the country, impacting senior feeding programs, school meals, and guidelines for other federal and non-federal programs. Because of the DGAs large impact, the government agencies want to ensure that the public gets a say throughout this process. This includes everyone from industry leaders to physicians to private citizens who are passionate about our country’s food and nutrition policy. This meeting included the second opportunity for the public to provide comments and while the themes were similar to the first public comments back in July there were several that stood out.
Low-Carbohydrate Diets: the current dietary guidelines define a low-carbohydrate diet as one with less than 45% of daily intake from carbohydrates. Some medical professionals and concerned citizens provided comments that support lowering the definition to a low-carbohydrate diet to no more than 25% of daily intake from carbohydrates.
Plant-Based Diets: the health benefits thought to be associated with this diet as well as the impact on the environment, makes this topic a hot button issue. Climate change and sustainability will not be addressed by this DGAC, however, it received a lot of attention during public comment.
Population Health Status: was an interesting topic that came up throughout the public comment period. Most of the population suffers from one or more chronic diseases which we know can be impacted by diet. Commenters and even some DGAC members brought up the fact that dietary guidelines are written for a general, healthy population although we do not have a general, healthy population in the US due to chronic diseases.
Industry Pressure: several commenters brought up the influence of industry in the dietary guidelines and how other countries, such as Canada, have removed industry pressure and influence from their guidelines. The irony wasn’t lost on this issue as many commenters represented a food industry or brand.
What’s Next for the Dietary Guidelines?
The work of the DGAC is truly winding down with one more public meeting in March and then a webcast that will present the committee’s report in May. Unfortunately, there were no groundbreaking conclusions presented at this meeting and the DGAC provided little hope that there would be any in this set of guidelines. Multiple committee members noted that we simply need more research on a lot of these topics, but they posed the question of who would pay for some of this research and there were no clear answers. Perhaps utilizing new advances in technology like apps or trackers will help us better understand what people are eating that can inform the next set of guidelines.
It will be interesting to see how the guidelines change from the previous edition to include the new life stage format and the new subcommittees. Working in public health nutrition I know the impact the dietary guidelines will have on food and nutrition policy. I also hope that our overall eating patterns will begin to shift more towards the guidelines as well. Stay updated on the work the DGAC is doing by visiting www.dietaryguidelines.gov and sign up to receive updates by email as well. It is exciting that next year at this time we will have a new set of dietary guidelines that we are implementing!
*This blog post was co-written with Allison Roselli, a Medical University of South Carolina Dietetic Intern