Increasing Saturated Fat Intake by Two Times does not Increase Saturated Fat in Blood
Saturated fat is made up of triglycerides that can lead to cardiovascular disease and obesity. Although saturated fat is bad for the body, increasing intake by two or even three times does not lead to an increase in saturated fat measured in the blood, a new study reported.
For this study, the researchers recruited 16 participants with metabolic syndrome and fed them a controlled diet. Metabolic syndrome occurs when people have at least three of the five factors that contribute to heart disease and diabetes. After the participants were all on a baseline reduced-carb diet, the team started to change the diet every three weeks for 18 weeks.
Throughout this time, they increased carbohydrates, kept protein and calories stable, and reduced total fat and saturated fat. The amount of fat that the participants ate was about two to three times higher than what they usually ate. Carb intake increased from 47 grams to 346 grams and saturated fat fell from 84 grams to 32 grams. Calories and protein levels remained the same at 2,500 and 120 grams respectively.
By the end of the experiment, the participants lost 22 pounds on average. In comparison to their baseline measurements, the participants had improved blood glucose, insulin and blood pressure. However, the increase in carbs was linked to a steady increase in a fatty acid that has been tied to a greater risk of diabetes and heart disease. The team also found that total saturated fat in the blood did not increase.
"It's unusual for a marker [fatty acid] to track so closely with carbohydrate intake, making this a unique and clinically significant finding. As you increase carbs, this marker predictably goes up," senior author Jeff Volek, a professor of human sciences at The Ohio State University said according to the press release. "When you consume a very low-carb diet your body preferentially burns saturated fat. We had people eat 2 times more saturated fat than they had been eating before entering the study, yet when we measured saturated fat in their blood, it went down in the majority of people. Other traditional risk markers improved, as well."
Volek concluded, "There is no magical carb level, no cookie-cutter approach to diet, that works for everyone. There's a lot of interest in personalized nutrition, and using a dynamically changing biomarker could provide some index as to how the body is processing carbohydrates."
The study was published in PLOS ONE.