Scientists say carbs—not fat—are the biggest problem with America’s diet

24 Dec, 2010

Just in time for the holiday-season blizzard of baked goods comes the news that carbohydrates—not fat—are more likely to be responsible for obesity, diabetes, heart disease, and the other ills of modern civilization. The Los Angeles Times has a detailed report on the growing body of scientific evidence that until now has been treated as nutritional poison: Fat is good, carbs are bad.

“The country’s big low-fat message backfired,” Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health, told the Times. “The overemphasis on reducing fat caused the consumption of carbohydrates and sugar in our diets to soar. That shift may be linked to the biggest health problems in America today.”

Remember Robert Atkins? He’s the guy who was nearly drummed out of the medical profession for proposing that the way to get slim and stay healthy was to eat lots of meat and fat, and abstain from bread and potatoes.

The Atkins diet struck many as pure craziness. But study after study has shown Atkins more right than wrong. Carbohydrates—meaning plant-derived foods—have been directly linked with elevated triglycerides (fat) in the blood; suppression of HDL, the so-called good cholesterol; increased production of low-density lipoproteins (LDL) that damage arteries; weight gain and high blood pressure.

Eating carbs triggers insulin, the fat storage hormone. Over-consumption can lead to insulin resistance, a precursor to Type 2 diabetes.

Put all of these carb-related problems together and you have what medical researchers dub “metabolic syndrome.” According to the Times, 25 percent of Americans now exhibit at least three of the major symptoms of the syndrome, which include elevated triglycerides, low HDL cholesterol, fat bellies, and high blood pressure.

Now, oversimplification runs both ways. Not all fat is “good”: the fat from feedlot beef and factory-farm pork and chicken, which are fed loads of carbohydrates, has a different nutritional profile, higher in heart-disease-linked Omega-6 fatty acids, than those that eat their natural diets and forage on pasture, which are rich in Omega-3s. (The Eat Wild website collects the scientific literature on the differences.) And not all carbs are “bad”: complex carbohydrates from whole-plant-based foods cause less of a spike in blood sugar than do refined carbohydrates, i.e. processed foods.