Background-01
These recommendations, known as the Dietary Guidelines for Americans, are far more pervasive than most people realize and in fact, have come to dominate our ideas about a healthy diet, via feeding assistance programs, various food policies, the advice promoted by most healthcare professional associations, K-12 nutrition education, and much more. Issued jointly by the U.S. Departments of Agriculture and Health and Human Services (USDA-HHS), the Guidelines inform:
- The National School Lunch Program (NSLP)
- Supplemental Nutrition Assistance Program educational programming (SNAP-ed)
- Special Nutritional Program for Women, Infants and Children (WIC)
- Military food programs
- Nutrition support for the elderly
- Back-of-package labeling on packaged foods
- Dietary advice dispensed by doctors, nurses, dieticians, nutritionists, and other health professionals
Because the Dietary Guidelines touch the lives of so many Americans, including many of our most vulnerable citizens, it is imperative that this policy be based on the best available science and provide advice that is inclusive of all Americans.
Some questions have been raised about the Guidelines in recent years, including:
Do the Dietary Guidelines Include all Americans?
Since the launch of the Guidelines in 1980, the policy has been designed only for “healthy” Americans. Although a majority of Americans were indeed healthy in 1980, this is no longer the case. The continued exclusive focus on disease prevention for “healthy Americans” has grave ramifications and limitations, since:
Those with diet-related, chronic diseases
The policy’s one-size-fits-all approach excludes the hundreds of millions of Americans with nutrition-related diseases.
To address this problem, the National Academies of Science, Engineering, and Medicine (NASEM), in a 2017 Congressionally mandated report, recommended that:
“The scope of the DGA should…be broadened such that future editions focus on the general public across the entire life span, including all Americans whose health could benefit by improving diet…”
Minorities and populations with different cultural backgrounds
Because the Dietary Guidelines largely dictate USDA feeding assistance programs, this policy has a distinct impact on minority populations, including African Americans, Hispanics, and indigenous communities, who disproportionately rely on federal nutrition-support programs and who also suffer from higher rates of chronic disease. In fact:
It is therefore highly important that the Guidelines offer a diversity of dietary options for these communities. The danger of excluding so many of our citizens, including those who are most in need of reliable nutrition advice, is an urgent issue that needs to be addressed by our nation’s leading nutrition policy.
Unfortunately, the Dietary Guidelines do little to address these urgent public health crises. To date, the USDA-HHS policy includes no nutritional advice tailored specifically to the elderly, individuals with different cultural backgrounds, or, perhaps most critically, those with one or more chronic, diet-related health condition.
How Strong is the Science Supporting the Recommendations?
Highlighting the desperate need to fund public health nutrition research, just 20% of the newly-graded evidence informing the 2015 guidelines received a “strong” rating, according to standards set forth by the USDA-HHS. *
The 2017 NASEM report recognized this challenge and, in response, stated:
“To develop a trustworthy DGA, the process needs to be redesigned.” (Page 51)
As a result, NASEM recommended that the USDA-HHS upgrade the Guidelines process to ensure greater rigor in the science that is used to underpin these nutritional recommendations.
According to NASEM:
“The DGA has to be based on the highest standards of scientific data and analyses to reach the most robust recommendations.“
To achieve this goal, NASEM recommended: “A redesigned process,” to include: “more rigorous methodological approaches to evaluation of evidence…” such that analyses “be based on validated, standardized, and up-to-date methods and processes.” (page 186) This NASEM report recommended that USDA-HHS adopt “state-of-the-art processes and methods to maximize scientific rigor,” such as “Cochrane, AHRQ, or GRADE.” (page 51)
Food4Health will work to ensure that the next iteration of the Guidelines serves two important goals:
That the Guidelines do more to provide nutritional advice for all Americans, not just those deemed to be “healthy,” AND
That the Guidelines be trustworthy, based in a rigorous, state-of-the-art scientific review methodology that reflects the best and most current science.
*
The Dietary Guideline Advisory Committee answers most scientific review questions by evaluating the science and issuing a through conclusion statement. These conclusion statement evaluates the science according to one of four categories, and ranks the evidence used to reach that conclusion. The four rankings are strong, moderate, limited, and grade not assignable.
“Strong” represents a conclusion statement supported by a “large, high-quality body of evidence that addresses the topic.” Ideally, this should include multiple clinical trials, since this is the type of study that can demonstrate cause-and-effect. The level of certainty should be high, unlikely to change, and generalizable to the population of interest.
“Moderate” represents a conclusion statement with sufficient evidence, but the level of certainty is restricted by the amount of evidence, inconsistency in the findings, or methodological or generalizability concerns.
“Limited” represents a conclusion statement that is substantiated by insufficient evidence, and certainty is severely restricted by the amount of evidence, inconsistent findings, or methodological or generalizability concerns.
“Grade not assignable” means a conclusion statement cannot be drawn due to the lack of evidence, or the evidence that is available has severe methodological concerns.