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Scientific Basis for Dietary Guidance 

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: Human Nutrition Research Priorities
: David Klurfeld506 31 Aug 2012
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Federal nutrition policy and food assistance programs increasingly use the Dietary Guidelines for American and Dietary Reference Intakes as their basis and these need to be updated based on new knowledge. We will identify the role of food, nutrients, other food components, and physical activity in promoting health and preventing disease.

1) Holly Greuling6 (20 Sep 2012)
The Dietary Guidelines are not appropriate for all 2+ year old age groups, especially the 85-110 year old cohort.
2) Barbara Schneeman12 (21 Sep 2012)
the needs in this area are two-fold: Evidence to support that implementation of the DGA has a positive health benefit for Americans and 2) research that improves the ability to make recommendations that are science-based.
3) Johanna Dwyer40 (24 Sep 2012)
Excellent topic. Not sure that USDA should be spending a lot of time on physical activity when so much remains to be done on food. Solid studies on the effects of the DGA on health of Americans (and perhaps also price comparisons) are needed. More evidence based reviews are critical. The notion of DG for <2 yr olds should be considered, for bottle as well as breast fed babies.also DG for the very old might be very interesting to develop. The use of more evidence based reviews in formulating the guidelines are extremely importance. More straightforward modeling would be helpful. More transparency not in the process of risk assessment, which is already quite good with more and more evidence based reviews, but more transparency in the deliberations that lead to risk management and communications /final messages in the DGA would be helpful (see for ex. Mackerras Food standards, dietary modeling and public health nutrition policy Nutrition and Dietetics 2012 69: 208-212.
4) Connye Kuratko16 (10 Oct 2012)
There is clearly a need for food-based guidance for defining a healthy diet. This USDA Idea should be supported. However, it is also clear that the US population is diverse and that many people either cannot or will not consume the recommended foods resulting from the Dietary Guidelines process. In an effort to reach as many people as possible, the DGs should consider making recommendations beyond the one major plan that will serve as a guide for the many food-based programs in this country. That advice should include limited but specific guidance regarding the use of supplements, fortified foods, or food combinations that would supply shortfall nutrients for those who cannot or will not eat meals that meet the recommendations of the DG Advisory Committee.
5) Kevin Miller12 (11 Oct 2012)
The metal content of some foods has become a recent topic making news (e.g., arsenic content of rice), but there is a need for science that can be used to weigh the positives associated with consumption of a food against the negatives which receive so much attention. Interagency cooperation is needed to assess the risk and benefits of food consumption.
A science-based position would help to promote the mostly healthful diet for the public.
What trade off exists for consuming whole foods? Many phytonutrients exist with reported benefits, but often the same foods are simultaneously criticized (e.g., soy isoflavones – pros and cons reported by different science-based research groups). How is the consumer to make decisions on a healthy diet?
6) Paul Paulsen18 (11 Oct 2012)
Increasing plant protein intake is not only for vegetarians but is promoted for those concerned about eating a more healthy diet and protecting the environment.
USDA Dietary Guidelines for Americans 2010 (DGA) states that on average, vegetarians consume a lower portion of calories from fat, fewer overall calories, have a lower body mass index which may contribute with other lifestyle factors to positive health outcomes – lower levels of obesity, reduced risk of cardiovascular disease, and lower total mortality. Further, the DGA encourages the population to seek lean sources of protein such as low fat meat, dairy and plant proteins.
Plant-based meat alternatives high in quality protein are lower in fat, cholesterol and calories. New developments by food scientists and culinary professionals have created products rivaling their meat containing counterparts in appearance and sensory experience. The benefits of these alternatives and their importance in a healthy American diet should be communicated through education, policy and extension programs.
7) Sarah Ohlhorst14 (15 Oct 2012)
A very important topic. Research is needed to better understand the ranges of Dietary Reference Intakes (DRIs) that support health maintenance in all population subgroups. Research is also need to help us better understand and minimize unfavorable impacts of elevated nutrient intake on health.

Research is also needed to show if, and how, dietary guidance drives behavior.
8) Marge Leahy19 (15 Oct 2012)
Evidence-based science needs to be the underpinning for all dietary guidance.
9) Sarah Levy12 (15 Oct 2012)
Grocery Manufacturers Association (GMA) comment: Nutrition science is constantly evolving. Frequent reevaluations of available science, and the inclusion of rigorous evaluation strategies, are necessary to ensure that U.S. dietary guidance is evidence-based. Dietary guidance should be applicable to the diverse U.S. population, including sub-groups such as Hispanics, African Americans, individuals living under lower socioeconomic conditions, prenatal women, infants/young children, and the elderly.

The scientific basis for dietary guidance must focus on food intake strategies with the greatest potential benefits to public health. To this end, research focused on individual nutrients and/or food components may not provide the greatest return on investment. While research on certain individual nutrients can increase general understanding of a nutrient’s function/mechanism and dietary benefits, often these strategies discount the relative contributions of multiple nutrients and food components in supporting overall health, as well as limit the creation of actionable guidance for consumers. Consumer research that shows how consumers actually implement the Dietary Guidelines for Americans (DGA) recommendations is needed.

The 2010 DGA includes recommendations for both nutrients/food groups to increase in the diet as well as nutrients/food groups to decrease. Additional research is needed to define each of these categories, particularly in the case of nutrients to limit. For example, the sodium recommendation made by the 2010 Dietary Guidelines Advisory Committee (DGAC) was severe and only considered blood pressure as an endpoint, despite some research studies (now supported by a larger body of evidence) suggesting that unduly restricted sodium intakes may lead to unintended health-related consequences (e.g. increased mortality) in population sub-groups. Furthermore, it is important to consider how recommendations designed to address concerns about individual nutrients may negatively impact overall recommendations for building healthy, balanced diets. Diet modeling data show that achieving low sodium intakes likely requires the displacement of other important nutrients, including potassium, a nutrient to increase according to the 2010 DGA. The entire scope of available evidence must be considered when making dietary guidance recommendations so that these unintended consequences are avoided.

USDA should leverage its own research expertise to identify research gaps and to execute research that addresses the recurring knowledge voids identified by the DGAC and adds to the evidence base that is important for dietary guidance. While USDA currently provides support with nutrient/food group intake analyses and evidence based analysis, its researchers are also positioned to provide more input upfront to help guide the DGA and deliver research findings that address major public health issues.

In addition, the evaluation of dietary guidance programs and recommendations is critical. Understanding the impact (or lack thereof) dietary guidance recommendations have on overall public health outcomes is necessary to inform future strategies and initiatives. Research that identifies the most effective strategies by which to evaluate these programs would be informative, and would also help to conserve valuable resources by all stakeholders in the future.