Low-Fat Diet Recommended By Federal Government May Have Unintended Consequences

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Main Category: Obesity / Weight Loss / Fitness
Also Included In: Nutrition / Diet;  Preventive Medicine
Article Date: 07 Feb 2008 - 0:00 PDT

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It is common knowledge that obesity levels in America have been recorded at record levels, almost reaching the point of an epidemic. However, in the wake of numerous federal guidelines that promote a low fat diet, one must beg the question -- is it possible that the government direction of dietary guidelines has somehow caused these unintended consequences, or is it just a coincidence?

In the March 2008 issue of the American Journal of Preventative Medicine, published by Elsevier, authors Paul R Marantz, MD, MPH, Elizabeth Bird, AB, and Michael H Alderman, MD, from the Albert Einstein College of Medicine explore just this question. In it, they suggest that the recommendations made by the government were based on limited scientific data and the implied assumption that it could do no harm. However, as evidence now may suggest otherwise, they warn that these guidelines may actually be harmful pending further study.

"When dietary guidelines were initially introduced in the late 1970s, their population-based approach was especially attractive since it was presumed to carry little risk," states Dr. Marantz. "However, the message delivered by these guidelines might actually have had a negative impact on health, including our current obesity epidemic. The possibility that these dietary guidelines might actually be endangering health is at the core of our concern about the way guidelines are currently developed and issued."

If the guidelines can alter the behavior of the public, it is possible that such alteration might have either positive or negative effects. According to the authors, in 2000, the Dietary Guideline Advisory Committee actually suggested that the lower fat diet recommendation advised in 1995 may have been ill-advised, and might in fact be harmful. This committee was concerned that "the previous priority given to a 'lowfat intake' may lead people to believe that, as long as fat intake is low, the diet will be entirely healthful. This belief could engender an overconsumption of total calories in the form of carbohydrates, resulting in the adverse metabolic consequences of high carbohydrate diets." The committee also noted that "an increasing prevalence of obesity in the United States has corresponded roughly with an absolute increase in carbohydrate consumption."

Multiple data sets presented by Dr. Marantz and his colleagues support these trends -- but the authors are carefully to specify that this correlation does not necessarily imply causation. Instead, according to Dr. Marantz: "it raises the possibility of a net harmful effect of seemingly innocuous dietary advice. These dietary recommendations did not necessarily cause harm, but there is a realistic possibility that they may have."

In the same issue of the American Journal of Preventive Medicine, Steven H. Woolf, MD, MPH, from Virginia Commonwealth University and Marion Nestle, PhD, MPH, of New York University assert that the federal guidelines are actually supported by decades of research. While they are united in the opinion that people often compensate for a low-fat intake level by consuming more calories in total, they disagree with the authors of the original article that the guidelines were inappropriate in promoting low fat diets. "The guidelines were not the culprit," according to Dr. Woolf, who believes that sharing the dietary causes of disease was the correct course of action.

Woolf and Nestle never call into question that guidelines can have unintended consequences. But, they write: "When the prevailing message fails to achieve its intended aims or achieves the wrong ends, the solution is not to abandon the enterprise but to reshape the message to achieve desired outcomes."

In a continuation of this parley, Marantz, Bird and Alderman gave further commentary. "When trying to mitigate potential harm from past guidelines based on inadequate science, issuing 'reshaped' guidelines with similarly inadequate science merely perpetuates past mistakes. It might sometimes be best to avoid translating flaccid arguments into rigid guidelines. Ultimately, this boils down to a difference in world view, much like the distinction between clinicians guided by the therapeutic imperative and those guided by the maxim 'first do no harm.' Of course, when the evidence is clear, beneficial interventions are always favored, and harmful interventions always shunned. It is when the data are unclear that challenges arise."
 
Marantz concluded, "As doctors, our first call is to do no harm. That's why we recommend that guidelines be generous in providing information, but more cautious in giving direction. Any directions should be based on the very highest standards of scientific evidence. After all, we expect that much from pharmaceutical companies before they bring a new drug to market."

A Call for Higher Standards of Evidence for Dietary Guidelines
Paul R. Marantz, MD, MPH, Elizabeth D. Bird, AB, and Michael H. Alderman, MD
American Journal of Preventive Medicine, Volume 34, Issue 3 (March 2008)
Click Here For Full Length Article

Do Dietary Guidelines Explain the Obesity Epidemic?
Steven H. Woolf, MD, MPH, and Marion Nestle, PhD, MPH
American Journal of Preventive Medicine, Volume 34, Issue 3 (March 2008)
Click Here For Full Length Article

The Authors Respond
Paul R. Marantz, MD, MPH, Elizabeth D. Bird, AB, and Michael H. Alderman, MD
American Journal of Preventive Medicine, Volume 34, Issue 3 (March 2008)
Click Here For Full Length Article

Written by Anna Sophia McKenney
Copyright: Medical News Today
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