Is Your Healthy Olive Oil Fueling Obesity? Study Finds Out

Researchers fed mice a variety of specialized diets enriched in specific individual fatty acids, including those found in coconut oil, peanut oil, milk, lard and soybean oil. Oleic acid was the only one that caused the precursor cells that give rise to fat cells to proliferate more than other fatty acids.

"You can think of the fat cells as an army," said Michael Rudolph, Ph.D., assistant professor of biochemistry and physiology at the University of Oklahoma College of Medicine and member of OU Health Harold Hamm Diabetes Center. "When you give oleic acid, it initially increases the number of 'fat cell soldiers' in the army, which creates a larger capacity to store excess dietary nutrients. Over time, if the excess nutrients overtake the number of fat cells, obesity can occur, which can then lead to cardiovascular disease or diabetes if not controlled."

Unfortunately, it's not quite so easy to isolate different fatty acids in a human diet. People generally consume a complex mixture if they have cream in their coffee, a salad for lunch, and meat and pasta for dinner. However, Rudolph said, there are increasing levels of oleic acid in the food supply, particularly when access to food variety is limited and fast food is an affordable option.

Reference: Allison Wing, Elise Jeffery, Christopher D. Church, Jennifer Goodell, Rocío del M. Saavedra-Peña, Moumita Saha, Brandon Holtrup, Maud Voisin, N. Sima Alavi, Mariana Floody, Zenan Wang, Thomas E. Zapadka, Michael J. Garabedian, Rohan Varshney, Michael C. Rudolph, Matthew S. Rodeheffer. Dietary oleic acid drives obesogenic adipogenesis via modulation of LXRα signaling. Cell Reports, 2025; 44 (4): 115527 DOI: 10.1016/j.celrep.2025.115527