The journal Nutrition just published a paper titled In The Face Of Contradictory Evidence: Report Of The Dietary Guidelines For Americans Committee. The authors are Adele Hite, MAT; Richard Feinman, PhD; Gabriel Guzman, PhD; Morton Satin, MSc; Pamela Schoenfeld, RD; and Richard Wood, PhD.
Let’s hope this gets some major media play. Sure, a lot of bloggers ripped the 2010 Dietary Guidelines for spouting the same old nonsense, but we’re bloggers, not academic researchers, so we’re easy to ignore.
It’s not so easy to dismiss this group, especially when their paper is published in a respected journal. Professional courtesy dictates they avoid the kind of language I would use to describe the Dietary Guidelines committee (morons, hacks, anti-fat hysterics, etc.), but if you read the paper, the message is clear: Nice attempt at wading through the research, kids … now stop going wee-wee in the pool and go dry yourselves off, because it’s time for the adults to swim — after we give you a well-deserved spanking, of course.
This paragraph from the abstract pretty much sums it up:
Although appealing to an evidence-based methodology, the DGAC Report demonstrates several critical weaknesses, including use of an incomplete body of relevant science; inaccurately representing, interpreting, or summarizing the literature; and drawing conclusions and/or making recommendations that do not reflect the limitations or controversies in the science.
It’s followed soon after by this paragraph from the paper’s introduction:
The DGAC Report had the opportunity to review and evaluate the emerging science, to distinguish between established principles and ideas that are still areas of research or controversy, and to provide clear, consistent information for Americans. Instead, the 2010 DGAC Report continues to make one-size-fits-all recommendations that are based on evidence that is weak, fragmented, and even contradictory in nature.
Yup, the DGAC coulda been contenders. They coulda had class. Instead, they got together and went wee-wee in the pool. In the Nutrition article, the adults call attention to the wee-wee. For example, the DGAC Report complains that Americans aren’t following the U.S. Dietary Guidelines, which of course call for consuming less fat and more carbohydrates. The adults beg to differ:
Average daily calories from meat, eggs, and nuts have increased by about 20 cal since 1970 as average daily calories from flour and cereal products have increased by nearly 10 times that amount (p. D1-10). In short, the macronutrient content of the diet has shifted in the direction recommended since the 1977 dietary goals.
Total and saturated fat intakes have decreased as a percentage of calories for men, the absolute amount has decreased whereas carbohydrate intake has increased. Notable from the DGAC Report is the absence of any concern that this shift in macronutrient content may be a factor in the increase in overweight /obesity and chronic disease; the proposed recommendations suggest that this trend should not only continue but also become more pronounced.
Well, it’s a government committee, so they had to adopt the government’s stategy for dealing with obvious failures: hold up the failure as proof that we need to do the same thing again, only bigger.
After pointing out the general wee-wee, the Nutrition article deals with many of the individual streams. In fact, the topic headings in the paper read like a list of charges. Here are few sample headings:
Macronutrients: Research questions are formulated in a way that prevents a thorough investigation of the literature
Macronutrients and weight loss: Science is inaccurately summarized
Low-carbohydrate diets: Science is inaccurately represented
Low-carbohydrate diets: Conclusions do not reflect quantity and/or quality of relevant science
Effects of saturated fat: Answers based on an incomplete body of relevant science
Effects of saturated fat: Science is inaccurately represented or summarized
Diabetes and fat: Science is inaccurately represented or summarized
Dietary fiber and whole grains: Conclusions do not reflect the quantity and/or quality of science
Salt: Recommendations do not reflect limitations and uncertainties of the science
You get the idea. Within each topic, the authors point out the many flaws in the scientific “evidence” cited to support the 2010 Dietary Guidelines … the cherry-picking, the incorrect conclusions, and the contradictions. If you’re interested in the details, you can read the full paper.
Towards the end of the paper, the authors present a little history:
It is of interest to consider the opinion of the American Medical Association (AMA) with respect to the first implementation of dietary guidelines. In an editorial, it was stated:
“We believe that it would be inappropriate at this time to adopt proposed national dietary goals as set forth in the Report on Dietary Goals for the United States. The evidence for assuming that benefits to be derived from the adoption of such universal dietary goals as set forth in the Report is not conclusive and there is potential for harmful effects from a radical long-term dietary change as would occur through adoption of the proposed national goals.”
In the three decades since, carbohydrate consumption has increased; overall fat, saturated fat, and cholesterol consumption have decreased to near or below targeted levels; caloric intake remains within recommended levels; and leisure-time physical activity has increased slightly (pp. D1-1, D3-10, B2-3). At the same time, scientific evidence in favor of these recommendations remains inconclusive, and we must consider the possibility that the “potential for harmful effects” has in fact been realized.
I don’t think we have to consider that possibility very deeply. If the potential for harm hasn’t been realized, I’d sure hate to see what real harm looks like.
In addition to calling for a halt to the “population-wide dietary experiment” that began in 1977 with the McGovern committee’s report, the authors suggest convening a group of impartial scientists to re-examine all the evidence. In the meantime, they say, it’s time for public officials and clinicians to stop blaming Americans for the obesity epidemic by claiming we’re not following the government’s advice.
Since I’m not writing for an academic journal, I’d put it a little differently: It’s time for the government’s nutrition “experts” to stop making wee-wee on our heads and telling us it’s raining.