Carbs Vs Saturated Fat: Which Should You Avoid?

An uptake in consumption of saturated fat does not increase saturated fat levels in the blood, but consuming more carbohydrates is related to higher levels of fatty acids associated with adverse health outcomes, according to a new study.

“Recent meta-analyses have found no association between heart disease and dietary saturated fat; however, higher proportions of plasma saturated fatty acids (SFA) predict greater risk for developing type-2 diabetes and heart disease,” said researchers.

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“These observations suggest a disconnect between dietary saturated fat and plasma SFA, but few controlled feeding studies have specifically examined how varying saturated fat intake across a broad range affects circulating SFA levels.”

In order to explore this disconnect, researchers followed 16 adults with metabolic syndrome on 2500 calorie diets, which included 130 g of protein.

Over the course of the 18-week study, researchers gradually decreased the amount of saturated fat in the participants’ diets while increasing the amount of carbohydrates. The first diet consisted of 47 g of carbohydrates and 84 g of saturated fat, and the last included 346 g of carbohydrates and 32 g of saturated fat.

While on the high-fat, low-carb diets, researchers found that levels of palmitoleic acid—a biomarker of obesity, insulin resistance, and heart disease—decreased.

Inversely, when switched to high-carb, low-fat diet, levels of the acid increased in all participants, indicating that the majority of consumed carbohydrates were being converted to fat rather than being burned off for fuel. 

“These findings contradict the perspective that dietary saturated fat per se is harmful, and underscore the importance of considering the level of dietary carbohydrate that accompanies saturated fat consumption,” researchers concluded.

—Michael Potts


1. Volk BM, Kunces LJ, Freidenreich DJ, et al. Effects of step-wise increases in dietary carbohydrate on circulating saturated fatty acids and palmitoleic acid in adults with metabolic syndrome. PLOS One. 2014 November 21 [epub ahead of print].  doi: 10.1371/journal.pone.0113605