Five years ago, Americans were told by a panel of experts that cholesterol in foods was bad for you. This week, that panel said, “Never mind.”

The reversal on cholesterol by the Dietary Guidelines Advisory Committee (DGAC), the group that provides the basis for our recommended daily diet, was not a shock to medical experts who say the evidence for a warning on cholesterol was “weak, at best,” according to The Washington Post.

“Looking back at the literature, we just couldn’t see the kind of science that would support dietary restrictions,” Robert Eckel, the co-chair of the task force and a medical professor at the University of Colorado, told the Post.

How could the DGAC target a nutrient for warnings when the evidence did not exist to do so? Because the system is broke, say medical experts.

Dr. Joanne Slavin, a professor in the Department of Food Science and Nutrition at the University of Minnesota and a former member of the 2010 DGAC, says the problem is that the DGAC too often pronounces opinions rather than advice based on a rigorous unbiased review of the best available science.

“We don’t have to travel very far back in time to witness examples of dietary guidance recommendations that were made prematurely and are now challenged as more research is introduced, wrote Slavin in a review published in Nutrition Journal just this month.

Dr. Steve Nissen, chairman of cardiovascular medicine at Cleveland Clinic, told USA TODAY that the advice not to eat eggs and other foods containing cholesterol was “never based on good science.”

“We got the dietary guidelines wrong,” he says. “They've been wrong for decades.”

As Slavin points out, DGAC recommended in the past that Americans avoid foods high in fat content. The advice led Americans to binge unhealthily on low-fat foods that were high in carbohydrates. Now the DGAC emphasizes healthy consumption of fats, such as those found in olive oil and salmon.

Just five years ago the DGAC said half of the U.S. population needed to reduce dramatically its sodium intake. But now, the Institute of Medicine (IOM), one of the country’s premier scientific bodies, along with the prestigious New England Journal of Medicine, is casting doubt on the recommendation, says Slavin.

“The 2010 DGAC recommendations are now inconsistent with our most recent scientific understanding of sodium and health,” Slavin points out in her review.

Which brings us to the DGAC’s latest recommendations. The panel this week recommended eating less red meat, processed meat, pork and cheese in part because these foods have “a larger environmental impact.” It also recommends raising taxes on beverages based on “moderate” evidence that they are “associated” with health problems.

Is this yet another example of the DGAC demonizing nutrients without the scientific evidence to back them up? Slavin, who is the author of more than 250 scientific publications and numerous book chapters and review articles on topics including dietary fiber, carbohydrates, whole grains, protein, and the role of diet in disease prevention, looks at the facts:

“Added sugars have become the current nutrition ‘watch out,’ believed by some to uniquely contribute to obesity and other adverse health outcomes,” she wrote. “However, the majority of scientific evidence shows that all sugars (added or intrinsic) … are no more likely to cause weight gain or negative health outcomes than other calorie sources.”

So why is it that the DGAC keeps making recommendations that fail to be based on “strong” science?

“Simply stated, the committee made a conscious decision to turn the (Dietary Guideline for Americans) into an advocacy and public relations exercise driven by emotion, assumptions and bias rather than fact,” states Sean McBride, founder of DSM Strategic Communications.

Slavin says the country has a vital interest in making sure “only the strongest, best available evidence” serves as the basis for helping consumers make healthy dietary choices. To do that, she recommends several changes be made to our dietary advice system, including:

-          Improve the way we grade the “quality” of nutritional evidence reviewed;

-          Ensure committees have a balanced and well-rounded set of perspectives and expertise;

-          Assess all relevant science, including research funded by the food industry

“It is imperative that food and nutrition policies reflect, and do not get ahead of, the strongest available scientific evidence,” Slavin says.