Americans are passionate about food. We’re not suggesting that they are fanatical about gourmet cooking like the French. After all, America is the home of fast food.

What gets Americans excited is dietary dogma, especially if it disagrees with what they have been told. That explains why sparks fly whenever the benefits of low-carb versus low-fat diets are discussed.

We recently interviewed Eric Westman, M. D., one of the authors of “The New Atkins for a New You.” This diet book summarizes recent research supporting a low-carb approach for weight loss and cholesterol control. While some listeners were pleased to hear of this approach, others were appalled. They left comments on our Web site such as:

“To promote anyone who says that saturated fats are less harmful than healthy carbohydrates is dangerous and disingenuous.”

Another opined:

“We’ve gone from demonizing one macronutrient [fat] to demonizing another [carbohydrates]. This is not productive. Successful weight loss does not come from swapping fat and carbs, it comes from eating fewer calories than are burned. . . . The tendency to demonize certain types of food just shows how far people will go to blame their weight problems on something other than how much they eat.”

This comment sums up the feelings of many listeners: “The overwhelming peer-reviewed, non-biased research from reputable journals shows Atkins-type diets to be unhealthy and ineffective.

“Ornish-type diets [low-fat] are healthy and effective as are other vegetarian and non-processed diets, and good research backs this up.”

People have been told for decades that fat makes you fat and saturated fat clogs your coronary arteries. These beliefs have been stated as fact by so many authorities for so long, they are ingrained in the American psyche. People have a hard time accepting data that do not confirm these views.

A new analysis from Harvard, however, could cause dismay among the diet dictocrats. The investigators assessed data from 20 studies that met quality criteria. More than 1 million people were included as subjects.

Here is the bottom line: “When all data were pooled, consumption of unprocessed red meat (e. g., unprocessed meat from beef, pork, lamb) was not associated with risk of coronary heart disease or diabetes mellitus” (Circulation online, May 17, 2010).

This conclusion is going to be very hard to swallow for both health professionals and the public at large. It flies in the face of long-established conventional wisdom.

That’s not to say the study let all meat products off the hook. This huge meta-analysis discovered that processed meats (bacon, hot dogs, salami, sausage, pepperoni, bologna, etc.) were linked to both heart disease and diabetes. The authors propose that the high sodium and nitrate preservative content of such packaged products may be the culprits.

Because U. S. dietary guidelines have emphasized limiting saturated fat for so long, many people see steak as a sinful indulgence that takes them one step closer to a heart attack. Perhaps they should be more concerned about hot dogs, bacon and bologna.