"The authors … use kilojoules to measure energy instead of calories, but when you convert the units, you'll see that few of the studies showed a benefit relevant to the real world. For example, one study found that 5 grams of MCT oil did indeed raise the metabolic rate of healthy men … by 11 calories a day … [Y]ou could burn more calories than that by walking for [five] minutes, or jumping rope slowly for [two] minutes."
In 2013, a landmark study of more than 7,000 people in Spain was published. The study’s subjects were split into three groups: those receiving advice about following a Mediterranean diet and getting extra-virgin olive oil delivered to their home; receiving advice about following the Mediterranean diet and getting nuts delivered to their home; and, in the control group, receiving advice about following a low-fat diet.
And monounsaturated fat isn't the only thing olive oil has going for it nutritionally. Some olive oils come with phytonutrients that may offer their own disease protection benefits (still, it's not clear whether most of us can take in enough of these phytonutrients without going overboard on olive oil, says Joyce Nettleton, DSc, RD, researcher and editor of the PUFA Newsletter).