It’s no wonder so many of us are confused about healthy eating. Even the nation’s dietary experts keep changing their mind about what we should eat and what we should avoid. We asked USC School of Pharmacy Research Professor Roger Clemens to help remove some of the confusion surrounding healthy fats.

Q: What are the latest dietary guidelines regarding fat and cholesterol?

Dr. Clemens: The 2015 Dietary Guidelines Advisory Committee Scientific Report states that cholesterol is no longer a nutrient of concern. The available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol. This is consistent with the conclusion of the American Heart Association and American College of Cardiology report.

Q: Can you explain this change in thinking over the past several decades?

Dr. Clemens: Nutritional science is dynamic. In the 1980s, the Dietary Guidelines suggested consumers avoid too much total fat and saturated fat. Over time, total fat guidelines have been upwardly adjusted with the 2010 Guidelines suggesting diets with up 35 percent of daily calories from fat. The 2015 executive summary suggests no upper limit for total fat consumption. Saturated fat guidelines have similarly evolved and now suggest including up to 10 percent in a healthy diet, and replacing saturated fat with polyunsaturated and mono-unsaturated fat. This thinking may still be changing, however. Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.
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