It is almost 3 weeks since the new 2015-2020 Dietary Guidelines for Americans were issued by the US Departments of Health and Human Services (DHHS) and Agriculture (USDA), and these were initially met with harsh criticism from many quarters.
Critics, including the Center for Science in the Public Interest and certain experts at Harvard and Yale, told various media outlets, including WebMD, that the guidelines were watered down and politically and industry influenced.
Others were more cautious: the American Medical Association remained relatively neutral, and the Academy of Nutrition and Dietetics came down in support of the guidelines.
Now that the dust has begun to settle, Medscape Medical News set out to gauge what some other experts are thinking, having had time to digest the information, and what they believe the new guidelines will mean for clinical practice.
Opinions remain somewhat divided.
There is most controversy regarding the quality of evidence on which the guidelines were based and on what specific foods they have omitted to single out as "bad." In addition, the charge is that the guidelines ignored advice to consider sustainability.
As background, the US Dietary Guidelines Advisory Committee (DGAC) reviewed scientific evidence and provided a report to the DHHS and USDA last February, which spoke to the issue of sustainability. DGAC also explicitly included the reduction of sugar-sweetened beverages and red and processed meat as goals in its report.
But specific reference to these foods was excluded from the new guidelines.
To be fair, the guidelines do recommend eating less meat overall and choosing leaner cuts, but these can include red and processed meats as long as the overall diet pattern remains within the recommended limits of salt, added sugars, and saturated fats.
In addition, chapter 1 details strategies for reducing added sugars and recommends "choosing beverages with no added sugars, such as water, in place of sugar-sweetened beverages, reducing portions of sugar-sweetened beverages, drinking these beverages less often, and selecting beverages low in added sugars."
But many experts still maintain the guidelines are not precise enough, missing opportunities for disease prevention, and they imply the hand of industry is at play.
DGAC Recommendations "Watered Down" and Sustainability Ignored
Yale University professor David L Katz, MD, MPH, has been particularly critical, calling the guidelines a "national embarrassment" in social medial posts, and noting in a Huffington Post editorial that these are "Guidelines to Balance Public Health and Corporate Profit."
Dr Katz asserts that these are "Food Policy Guidelines for America" rather than dietary guidelines and has started an online petition to try to change the name.
Another heavy hitter, Walter Willett, MD, MPH, DPH, of the Harvard TH Chan School of Public Health, agrees. "Clearly these guidelines bear the hoofprints of the Cattleman's Association and the sticky fingerprints of Big Soda. They fail to represent the best available scientific evidence and are a disservice to the American public," he wrote in an online editorial.
The report of the scientific committee [DGAC] "was very clear about the adverse health effects of red and processed meat and sugar-sweetened beverages, and the USDA has engaged in censorship and obfuscation," Dr Willett added.
Richard Wender, MD, chief cancer control officer for the American Cancer Society, said when the guidelines were released that "by omitting specific diet recommendations, such as eating less red and processed meat, these guidelines miss a critical and significant opportunity to reduce suffering and death from cancer."
One member of the 2015 DGAC, Frank B Hu, MD, PhD, also of the Harvard TH Chan School of Public Health, says that important recommendations made by DGAC — like those about red and processed meats and sugar-sweetened beverages — have been "watered down" compared with the initial DGAC report.
Dr Hu also stressed — in an online Q&A session — that environmental sustainability, a "major topic" of the DGAC report, was "unfortunately declared out of the scope of the Dietary Guidelines for Americans by the USDA, due to political pressure from Congress and the meat industry."
Interviewed by Medscape Medical News, Pamela A Koch, EdD, of Teachers College, Columbia University, agrees wholeheartedly: "The way that the dietary guidelines are written is, in my opinion, not clear. I wish that they had been much more specific about what foods not to eat."
"Sugar-sweetened beverages really should have been called out, and I think that they did not want to offend industry," she noted.
And the decision to exclude sustainability was definitely politically motivated, according to Dr Koch.
"The decision to not include sustainability...was, from the minute the report came out a year ago, [met with] pressure from industry saying don't include this," she revealed.
Defending the Guidelines…
On the other hand, Alice H Lichtenstein, DSc, vice chair of the DGAC and professor of nutrition, science, and policy at Tuft's University, Boston, Massachusetts, said that she doesn't understand how some people are saying that the guidelines are not precise enough.
"I'm wondering if some of the criticisms are well thought out and if everyone read the full documents. The guidelines are specific all over the place," she countered.
"It specifically says cut back on foods and beverages that have added sugar."
Furthermore, fine tuning and criticizing small details is not the "major point," according to Dr Lichtenstein.
"The major point is acknowledging that it's the whole diet," she emphasized,
"For dietary guidelines that are from a public-health perspective and aimed at a population that's so diverse in terms of chronic disease risk, age, and body weight, it is appropriate for guidelines to be relatively general. It's not really practical in guidelines for an entire population to get down to specific details, particularly about individual food."
But Where's the Evidence?
That said, other experts have scrutinized the quality of the research on which the guidelines are actually based.
Whether or not the guidelines are politically influenced is less important than having an overreliance on population studies "that really just show associations, which should never be confused with cause and effect," Keith Ayoob, EdD, of Albert Einstein College of Medicine, Bronx, New York, explained to Medscape Medical News.
The real problem is the dearth of high-quality randomized controlled trials in nutrition research.
This viewpoint is reflected in an editorial published online January 19 by Steve Nissen, MD, of the Cleveland Clinic, Ohio (Ann Intern Med. 2016; DOI:10.7326/M16-0035).
"[A] detailed review of the new guidelines conﬁrms a disturbing reality: the nearly complete absence of high-quality randomized, controlled clinical trials [RCTs] studying meaningful clinical outcomes for dietary interventions," he writes.
"The report repeatedly makes recommendations based on observational studies and surrogate end points, failing to distinguish between recommendations based on expert consensus rather than high-quality RCTs."
"Unfortunately, the current and past US dietary guidelines represent a nearly evidence-free zone," Dr Nissen asserts.
Criticism about the quality of the research started when the DGAC released its report to the DHHS and USDA last year.
In a "special article" published June 9 in Mayo Clinic Proceedings and widely critiqued online, Edward Archer, PhD, Gregory Pavela, PhD, of the University of Alabama, Birmingham, and Carl Lavie, MD, of Queensland University, Australia, and the John Ochsner Heart and Vascular Institute, New Orleans, Louisiana, said the main source of scientific information used by the DGAC came from "fundamentally flawed" studies based on memory-based food recalls (Mayo Clin Proc. 2015;90:911–926).
Such studies are "pseudoscientific" and "scientifically inadmissible," they asserted, because people often fail to recall exactly what they eat. National guidelines should not be based on data from such trials, they declared.
Health researchers Brenda Davy, PhD, RD, and Paul Estabrooks, PhD, of Virginia Tech in Blacksburg, countered in an editorial in the same issue that the limitations of self-reported diet and physical activity are well recognized and acknowledged and can be offset by using various data sources (Mayo Clin Proc. 2015;90:845–847).
Drs Davy and Estabrooks also point out that two of the three authors [Archer and Lavie] of the special article reported financial relationships with the Coca-Cola company, "a major funder of efforts to criticize the DGAC."
They also pointed out that the DGAC has already highlighted the need for more RCTs to strengthen the evidence base and the need for dietary biomarker research.
"I think the guidelines committee would be the first to admit, sometimes they don't have enough good information, but they have to base it on available evidence, warts and all," Dr Ayoob pointed out.
Keep an Eye on the Big Picture: What About Advice for the Public?
Keeping an eye on the ultimate aim is what's important, according to Dr Lichtenstein.
"To retain some credibility in the eyes of the general public and to encourage continued shifts toward healthier eating patterns I think we really need to keep our eyes on the big picture rather than finding ways to undermine the DGAC," she said.
So what does that mean for healthcare providers?
"You have to give a nod to what's practical. These are guidelines, not prescriptions. Using them as prescriptions for an individual is misguided," Dr Ayoob told Medscape Medical News.
The key point is providing practical recommendations for change, Dr Lichtenstein asserted.
For example, if someone is eating too much processed meat, that could be because they have few options in their workplace. Suggestions to improve the quality of their diet could include bringing their lunch from home or buying it from other places with options besides processed meats.
Another example: help people spend their sugar calories wisely, Dr Ayoob commented.
A good place to spend sugar calories is on driving the consumption of yogurt in place of sugar-sweetened beverages. Most people prefer to eat sweet yogurt, and most people are not getting enough calcium and probiotics, he explained.
Dr Lichtenstein says that major changes are not necessarily needed. Shifting various components to a healthier overall dietary pattern may be all that's required.
"From the perspective of clinicians it's likely that there's going to have to be some individualization for each patient," she said, "It may seem like a major task, but it probably only needs to be done occasionally."
Shift to Nutrient-Dense Foods, Adapt as Needed
In general and to recap, the guidelines focus on an overall dietary pattern rather than individual components like food groups and nutrients. They recommend a shift to an overall eating pattern that is "nutrient-dense foods" and can be adapted to individual and cultural preferences, as well as budgetary constraints.
The five key guidelines include:
Follow a healthy eating pattern across the lifespan.
Focus on variety, nutrient density, and amount.
Limit calories from added sugars and saturated fats and reduce sodium intake.
Shift to healthier food and beverage choices.
Support healthy eating patterns for all.
The guidelines state that a healthy eating pattern includes a variety of vegetables (dark green, red, orange); fruits (especially whole fruits); grains (especially whole grains); low-fat and fat-free dairy; lean meats and other proteins like seafood, eggs, legumes, and nuts; and oils (especially plant-based).
In addition, Americans should consume less than 10% of calories per day of added sugar, less than 10% of calories per day from saturated fats, and less than 2300 mg of sodium per day; limit alcohol intake; and meet recommended physical-activity requirements.
The new guidelines got rid of the previous 2010 recommendation to decrease cholesterol to 300 mg/day, replacing it with the recommendation that people should eat as little cholesterol as possible.
Recommended proteins now include eggs, along with seafood, lean meats, and poultry, legumes (beans and peas), and soy products, as well as nuts and seeds.
And for the first time the new guidelines put a quantitative limit on added sugars and do not recommend restricting total fat (basically recommending a diet low in saturated fat, rather than low fat overall).
"People should think about dietary patterns as opposed to individual nutrients in foods. Within the larger dietary picture there's a lot of capacity for fine-tuning to personal preferences," Dr Lichtenstein concluded.
Dr Koch, Dr Ayoob, Dr Lichtenstein, Dr DeSalvo, Dr Olson, Dr Casavale, Dr Pavela, and Dr Nissen report no relevant financial relationships. Dr Archer reports honoraria from the International Life Sciences Institute and the Coca-Cola Company. Dr Lavie reports consulting fees and speaking fees from the Coca-Cola Company and is the author of The Obesity Paradox with potential royalties.
Medscape Medical News © 2016 WebMD, LLC
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Cite this: After Dust Settles, Mixed Reaction to New US Dietary Guidelines - Medscape - Jan 25, 2016.