Olive Oil and Fat Loss: The Science

EVOO Decreases Waist Size and Burns Fat

Olive oil is known for being heart-friendly, but it can also be a friend to your waistline. Here’s the science and how much to slurp down.

Olive Oil Reduces Waist Size? Come On!

Olive oil is a bit of a paradox. And if you’re a science fiction fan, you know all about paradoxes. The classic example involves time travel. You go back in time and accidentally kill your grandfather, which prevents him from knocking up your grandmother. Your dad never gets born, so you never get born and won’t be able to travel to the past to accidentally kill your grandfather. Paradox.

There are paradoxes in nutrition, too, like extra virgin olive oil (EVOO). It’s a pure fat, a combination of monosaturated (73%), saturated (14%), and polyunsaturated (11%) oils. A tablespoon contains 119 calories.

You’d think that drinking substantial amounts of it would go straight to your belly and love handles. But oddly enough, in reasonable amounts, EVOO acts in the opposite manner. Used correctly, it seems to reduce body fat and waist circumference, at least in overweight people. It helps lean people burn fat too, but through an entirely different mechanism.

That is a paradox that deserves exploration.

A Painless Synopsis of the Research

Look at the results of just a few studies involving EVOO and fat loss:

  • A 2017 study found that overweight women who supplemented their breakfast with 25 mL (approximately 1.7 tablespoons) of EVOO lost significantly more weight (80%) than women consuming an equal amount of soybean oil. The EVOO women also exhibited a reduction in blood pressure.
  • A 2006 study tracked more than 7,000 college students for two years and found that eating higher amounts of EVOO (by following a classic Mediterranean diet) didn’t lead to weight gain.
  • A 2008 study tracked 322 moderately obese subjects over two years. Those that followed a high-EVOO, Mediterranean diet lost nearly twice the weight as those that followed a low-fat diet.
  • A 2020 study with 23 subjects found that supplementing with EVOO for two months led to reduced body weight and reduced waist circumference.
  • A 2021 study that tracked 49 subjects over two years found the EVOO supplementation led to increased brown adipose tissue (BAT) activity in lean but not overweight/obese subjects.

How is All That Possible?

One theory is that the oleic acid in EVOO downregulates the production of an enzyme named SCD1, which favors weight loss. SCD1 deficient mice, for instance, consume 25% more food than normal mice but accumulate less fat and are thinner than their normal counterparts.

Another line of thinking is that metabolic syndrome is a “constellation of disturbances detrimentally affecting the metabolic homeostasis of an individual, where metabolic overload induces stress reactions, such as oxidative, inflammatory, organelle and cell hypertrophy, leading to a vicious cycle where environmental, genetic, and psychosocial factors interact through complex networks (Patti, et al., 2021).”

Whoa, that’s a big matzo ball of biochemical jargon. Anyhow, the thinking is that oleocanthal, the predominant polyphenol in EVOO (the one that causes your throat to burn when you swig it down), is a powerful non-steroidal anti-inflammatory, 9 mg. of which are equivalent to taking 90 mg. of ibuprofen.

This anti-inflammatory effect mitigates the stress reactions mentioned above. This, in turn, somehow mitigates the severity of metabolic syndrome, leading to less fat gain or even fat loss in obese people.

But EVOO isn’t friendly to just clinically obese people. It seems to help lean people stay lean, or maybe even sculpt away some of their low (but still undesirable to them) levels of fat. It seems it does this because the oleic acid it contains can stimulate brown adipose tissue (BAT).

BAT is a type of fat that’s more metabolically active than its white counterpart. Generally, it’s activated by exposure to cold or certain “adrenergic” drugs (those that mimic epinephrine or norepinephrine).

Say, for instance, you were somehow able to withstand sitting naked for extended periods in a room where the temperature was below 40 degrees Fahrenheit. You would likely start to shiver, which would trigger muscles to secrete a hormone that stimulates brown fat cells to use energy. Using more energy means that carbohydrates and fats are used as fuel, ultimately resulting in fat loss.

EVOO mimics that shivering, hormone-secreting effect, at least in lean(er) people (fat people don’t have much brown fat).

How to Use This Info

Now, no one is suggesting that EVOO is the key to slimness and rippliness. However, it appears to make those goals a little more easily attainable. So, if you’re at peace with the EVOO paradox and want to incorporate more of it into your diet, there are several easy ways to do it.

I recommend getting around 3 tablespoons of EVOO a day, perhaps evenly divided between breakfast, lunch, or dinner. I routinely add it to my morning oatmeal or my oat milk, protein powder, and mixed berry morning gruel.

  • You can use it to make your lunchtime chicken or tuna salad instead of mayonnaise.
  • Drizzle it over your salad or steamed vegetables.
  • Fry with it (the notion that its smoke point is too low for frying is a myth).
  • Use it in baking instead of butter (if a recipe calls for 4 tablespoons of butter, use 3 tablespoons of olive oil).
  • Add it to your protein drinks.

Another trick I learned from coach Dan John is to swallow a tablespoon of it between meals to suppress your appetite during dieting phases. Sure, it stings a little, but big deal, right?

Regardless of the research, you may still be wary of adding that much fat to your diet. I get that, but you’ve no doubt heard that “all calories are not created equal,” right? Well, EVOO is an example of that.

And, even if you’re one of the two or three people in the world who isn’t necessarily interested in getting leaner, EVOO and olive oil, in general, confer many other health benefits that make taking it worthwhile.




  1. Álvarez-Amor L et al. Extra virgin olive oil improved body weight and insulin sensitivity in high fat diet-induced obese LDLr−/−.Leiden mice without attenuation of steatohepatitis. Sci Rep. 2021;11 Article number:8250.
  2. Patti AM et al. Daily Use of Extra Virgin Olive Oil with High Oleocanthal Concentration Reduced Body Weight, Waist Circumference, Alanine Transaminase, Inflammatory Cytokines and Hepatic Steatosis in Subjects with the Metabolic Syndrome: A 2-Month Intervention Study. Metabolites. 2020 Oct 2;10(10):392. PubMed.
  3. Piers LS et al. Substitution of saturated with monounsaturated fat in a 4-week diet affects body weight and composition of overweight and obese men. Br J Nutr. 2003 Sep;90(3):717-27. PubMed.
  4. Monford-Pires M et al. Short Dietary Intervention with Olive Oil Increases Brown Adipose Tissue Activity in Lean but not Overweight Subjects. J Clin Endocrinol Metab. 2021 Jan 23;106(2):472-484. PubMed.
  5. Shai I et al. Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. N Engl J Med. 2008 Jul;359:229-241.