Just when the nutrition science community thought they had it right, they got it better. Based on the premise that we should certainly enjoy our food but choose wisely and eat less of it, the 2010 Dietary Guidelines for Americans was released in early 2011. Redesigned every 5 y since 1980 and mandated in 1990 by the National Nutrition Monitoring and Related Research Act, the Dietary Guidelines provides an important blueprint by which the federal government fashions its nutrition policies and formulates its education, outreach, and food assistance programs.
Historical perspective
In 1978, the U.S. Department of Agriculture (USDA) and the U.S. Health and Human Services (HHS; then the Department of Health, Education, and Welfare) voluntarily appointed a joint scientific task force to develop nutrition guidance statements. This initiative resulted in the 1980 Dietary Guidelines for Americans, which comprised 7 dietary recommendations (e.g. maintain ideal weight and avoid too much sodium) and an accompanying 20-page booklet. Since that time, the development of the Dietary Guidelines has become more codified, evidence based, and transparent and has resulted in lengthier and more detailed new guidance documents on a quinquennial basis.
For its most recent rendition and to allow the newest Dietary Guidelines to be firmly rooted in the most up-to-date scientific evidence, the USDA and HHS in 2008 appointed 13 prominent experts in nutrition and health to serve on a fresh Dietary Guidelines Advisory Committee. This noticeably transdisciplinary committee, chaired by Dr. Linda Van Horn (a clinical nutrition epidemiologist at the Northwestern University Feinberg School of Medicine), was charged with reviewing the 2005 Dietary Guidelines, determining whether revisions were warranted, and providing recommendations for these revisions.
Process: focus on evidence-based review and transparency
The committee quickly determined that, based on the wealth of new evidence, revisions were needed. They then set about not only developing new recommendations but also launching several important improvements to the process. These included use of the USDA's Nutrition Evidence Library, allowing application of rigorous, systematic, and transparent methodology while assessing published literature related to nutrient or food intake and health outcomes. The committee also developed an easily retrievable and searchable Dietary Guidelines website (www.dietaryguidelines.gov) designed to house all of the content and information relative to their deliberations. Further, a system was implemented to encourage extensive public comment and make this dialogue available for public viewing. Easily accessible webinars were made available for broadcasting the committee's meetings, and public meeting documents and audio recordings were made available online for continued public access beyond the initial meeting date.
In June 2010, a year and a half and 6 meetings later, the committee submitted their 452-page findings to the secretaries of the USDA and HHS. This report included not only specific recommendations and strategies for optimizing nutrient intake but also 2 chapters not included in previous reports. These chapters, entitled “The Total Diet: Combining Nutrients, Consuming Food” and “Translating and Integrating the Evidence: A Call to Action” as well as other more nutrient-focused chapters set the stage for the subsequent 7th edition of the Dietary Guidelines for Americans. Specifically, the committee's report emphasized an urgent need to address obesity at every stage of the lifespan (especially in childhood), while preventing nutrient deficiencies and imbalance, and changing the overall “food environment” to encourage and allow all people to choose healthier food patterns.
The recommendations
The resultant 2010 Dietary Guidelines for Americans put forth a total of 23 general and 6 special recommendations concerning optimal food and nutrition consumption. These recommendations were inspired by 4 major “action steps” for the American public:
Maintain energy balance: Reduce the incidence and prevalence of overweight and obesity of the U.S. population by reducing overall energy intake and increasing physical activity.
Focus on nutrient-dense foods: Shift food intake patterns to a diet that emphasizes vegetables, cooked dry beans and peas, fruits, whole grains, nuts, and seeds. In addition, increase the intake of seafood and fat-free and low-fat milk and milk products and consume only moderate amounts of lean meats, poultry, and eggs.
Reduce added sugars, solid fats, and sodium: Considerably reduce intake of foods containing added sugars and solid fats, because these dietary components contribute excess energy and few, if any, nutrients. In addition, reduce sodium intake and lower intake of refined grains that are coupled with added sugar, solid fat, and sodium.
Stay active: Meet the 2008 Physical Activity Guidelines for Americans.
At first glance, these overarching recommendations may seem like nothing new. And, aside from some minor housekeeping shifts (e.g. dried beans are now considered both a vegetable and member of the high-protein foods group; elimination of a discussion concerning discretionary calories; and transforming the Food “Guide” into Food “Patterns”), the basic tenets of the new Dietary Guidelines are similar to previous versions. However, dig a little deeper and some important and profound differences emerge.
What's new?
For instance, the specific recommendation for sodium intake now goes beyond advising the general population to consume no more than the Institute of Medicine's Tolerable Upper Intake Level (2300 mg/d). It also urges individuals with increased risk for cardiovascular disease (one-half the U.S. population) to lower their sodium intake even more to 1500 mg/d sodium. In addition, the much-debated issues of fish consumption during pregnancy and alcohol consumption during lactation are addressed. Vegetarian options and ethnic diversity are frequently referenced and accommodated. And, because the committee utilized a systematic review of the literature, recommendations are couched in terms of level of research rigor, a major and unparalleled improvement from previous Dietary Guidelines. Moreover, this document goes one key step further than any previous version. That is, it dares to state quite publicly that, although individuals and families make the final decisions related to what they will and will not eat, healthy choices cannot be made if they are not acceptable or available. As such, the Dietary Guidelines’ final chapter provides an unprecedented call to action urging all stakeholders to work together to ensure that each and every American has access to nutritious foods and opportunities for physical activity.
Summary
Although some will insist that the 2010 Dietary Guidelines for Americans offers the same “moderation, variety, and balance” mantra as provided previously, this argument is clearly unfounded. Rather, this document represents an important step forward for nutrition scientists, public health professionals, and the general public. As our first Dietary Guidelines document based on a systematic, evidence-based review of the literature embedded in a holistic view of the complexity of our food environment, this publication will serve well to inform individual Americans which dietary patterns are proven effective in improving health outcomes. It will also provide a versatile template by which public health agencies can design, implement, and evaluate nutrition-related programs; and food manufacturers can contribute by developing and marketing more healthful food items. We can be encouraged that nutrition scientists will continue to not only get it right but also get it better. After all, as scientific understanding of how health and nutrition are related evolves, so should our dietary recommendations.
For more information
Free copies of the full report as well as summaries and other related information are available at http://www.cnpp.usda.gov/DGAs2010-DGACReport.htm. The Report of the 2010 Dietary Guidelines Advisory Committee is available at http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/DGAC/Report/2010DGACReport-camera-ready-Jan11-11.pdf. Text of the 1990 National Nutrition Monitoring and Related Research Act can be found at http://uscode.house.gov/download/ pls/07C84.txt/; the USDA's Nutrition Evidence Library can be accessed at www.NutritionEvidenceLibrary.gov (or www.NEL.gov); and the 2008 Physical Activity Guidelines for Americans can be reviewed at http://www.health.gov/paguidelines/.