It is widely known that western-style diets typically contain a larger proportion of saturated fat. We previously wrote in our article on Low Carb Diets, Weight Loss, and Fat that palmitic acid, which is a fatty acid contained in meat, dairy, and other products, can negatively affect key signals from metabolic hormones. It dulls signals from insulin, and interferes with the brain’s ability to moderate the amount of food consumed. It turns out that not only does certain types of saturated fat affect your sense of satiety as we discussed in that article, but they also seem to keep you fat by slowing down metabolism. A 2005 study titled by Kien et al. “Increasing Dietary Palmitic Acid Decreases Fat Oxidation and Daily Energy Expenditure”, published in the Journal of Clinical Nutrition, finds that western-style diets, which are typically high in palmitic acid and other saturated fats, slow down metabolism. In fact, according to the authors, it is possible to speed up metabolism by switching to foods that contain healthy fats, or minimizing the proportion of saturated fats in one’s diet.

Research Findings: How Saturated Fat Slows Metabolism

Earlier research, such as by DeLany et al. in 2000, concluded that not all fat was metabolized equally fast by the body. This experiment compared the Mediterranean-style diet, which the authors define as the diet of the people of Greece and southern Italy in the 1960, to the western-style diet. The largest difference was the proportion of palmitic acid, a particular fatty acid. The Mediterranean-style diet contained 78.4g of oleic acid (principal fatty acid in olive oil) per 100g of fat, while the western diet contained 42g of palmitic acid per 100g of fat. Except for this difference, the diets provided the same amount of calories, and the people that participated in the experiment had similar body types. The study ran for eight weeks.

The authors reported that by the end of the study, the metabolism of the people that consumed the western-style diet slowed down significantly – by an average of 214 calories per day. While it may not seem as much, this is about the same as two snacks, each day. Stated differently, 214 calories is around 10% of the typical daily calorie requirement for a typical adult. At the end of the year, these 214 calories per day amount to a weight gain of about 22 lbs.

Increase Metabolism and Lose Weight

From this research, it appears that simple dietary changes can alter metabolism. By changing the fat composition, the Mediterranean diet group increased metabolism by an average of 9 calories per day. While this amount is not large, every calorie counts when losing weight is the goal. Simple substitution of one type of fat for another appears to cause an increase in metabolism. An example of such simple substitution is using olive oil or butter-substitute spreads containing it in place of butter, or other oils.

Kien and co-authors also note that not only does following a diet that contains a higher proportion of palmitic acid produced a reduction of 214 calories per day, it actually caused a small weight gain in as short a period as the 8-week length of this study.

Losing Weight by Raising Metabolism

What can we conclude from this research? It does not appear to be difficult to raise metabolism naturally. A simple change, as seen in this experiment, can account for a significant part of keeping metabolism up. If incorporated into a carefully thought through and advised diet and exercise routine, such changes can add up to successful, long-term weight loss and health. As always, please consult with your physician before embarking on any diet or exercise routine.

Other Resources

Low Carb Diets, Weight Loss and Fat on 20BMI.com
Exercising for weight Loss on 20BMI.com

Works Cited

Kien, C. L., Bunn, J. Y., and Ugrasbul, F. Increasing Dietary Palmitic Acid Decreases Fat Oxidation and Daily Energy Expenditure. Am J Clin Nutr 2005;82:320-6

DeLany JP, Windhauser MM, Champagne CM, Bray GA. Differential Oxidation of Individual Dietary Fatty Acids in Humans. Am J Clin Nutr 2000;72:905–11.