Don’t fear fats; be cautious with carbs

An oversimplification of diet advice that began in the 1970s—that people should steer clear of saturated fats to avoid heart disease and stroke—led to an unhealthy “fat phobia” in the U.S., according to nutrition expert Frank Hu of Harvard T.H. Chan School of Public Health.

To avoid fats, many Americans turned instead to reduced-fat and fat-free foods that were high in carbohydrates. But that contributed to an alarming rise in obesity and type 2 diabetes.

“The mistake made in earlier dietary guidelines was an emphasis on low-fat without emphasizing the quality of carbohydrates, creating the impression that all fats are bad and all carbs are good,” said Hu, professor of nutrition and epidemiology, in an October 19, 2015 New York Times article. “It’s really important to distinguish between healthy fats and bad fats, healthy carbs and bad carbs.”

While the saturated fats found in meats and dairy products isn’t healthy, other fats—like olive oil, canola oil, avocado and nut oils—is monounsaturated and doesn’t raise cholesterol or lead to blocked arteries the way saturated fats do. “Olive oil is important,” Hu noted. “It’s beneficial for cardiovascular health and body weight.”

The article also cited work by David Ludwig, professor in the Department of Nutrtion at Harvard Chan School, that showed that it’s important to consider the glycemic index of foods, which measures how quickly they are able to raise blood glucose. Foods with a high glycemic index—such as potatoes, white bread, and white rice—raise blood levels of glucose rapidly, which in turn prompts the secretion of insulin to process that glucose. Too much of these foods can lead to insulin resistance, type 2 diabetes, fatty liver disease, obesity, and cardiovascular disease.

Read the New York Times article: The Fats You Don’t Need to Fear, and the Carbs That You Do

Learn more

Fats and Cholesterol (The Nutrition Source)

Carbohydrates and Blood Sugar (The Nutrition Source)