Burn 220 More Calories a Day Without Trying

Fish Oil Boosts Fat Burning by More Than 10%

A small amount of this healthy supplement raised the resting energy expenditure rates of athletes by a surprisingly large amount.

Time to add another benefit to the long list of benefits already attributed to fish oil or, more accurately, to the omega-3 fatty acids that are so plentiful in many cold-water fishes.

So far, the list includes cardiovascular benefits, decreased inflammation, better reproductive health (including bigger, “better” balls), help with depression, improvement of cognitive disorders, and even improved sports performance as it improves the functional capacity of muscle cells.

There’s even evidence that fish oil can help with almost any malady affecting the human body. Go ahead and Google “fish oil” and the name of any human condition or disease you can think of. I’ve tried this a bunch of times and it’s the rare occasion when I don’t hit research paydirt.

For example, I just tried one that I thought would finally defeat fish oil: Corns. Yeah, as in, “I got bad feet, my corns hurt, to top it off I’m late for work.” Turns out fish oil can even help with them.

So, it shouldn’t surprise you when I tell you that fish oil has now been found to increase the resting energy expenditure of athletes by more than 10 percent. That’s right, taking fish oil helps athletes burn calories – a lot more calories – even when athletes were sitting in their rooms, admiring their reflection in all their medals and trophies.

What They Did and What They Found

I’ll make it short. Tabriz University of Medical Sciences in Iran. Thirty-six professional athletes divided into two equal groups. One group took two capsules of fish oil every day for 3 weeks while the other group was suckered into taking a placebo.

After the 3 weeks, the athletes who took the fish oil were found to be burning up 220 more calories (kilocalories) at rest than they did before the study started. That means their basal metabolic rate increased by 10.67 percent. The placebo group? Not so much. As expected, their metabolic rate didn’t change.

So, What in the Wide, Wide, World of Sardines Explains the Results?

Other fish oil studies, mostly using murine models (mice or rats), have found that EPA/DHA (the two major omega-3 fatty acids) supplementation increased resting energy expenditure by notching up fatty acid oxidation, which is science-ese for the process by which the body breaks down fats for energy.

The Iranian group, however, suspected that fish oil, in addition to increasing fatty acid oxidation, upregulated a process called PPAR-gamma (peroxisome proliferator-activated receptor gamma) mRNA expression.

PPAR-gamma activates genes that regulate fatty acid storage and glucose metabolism. It also increases insulin sensitivity by enhancing the storage of fatty acids in fat cells. It does this by convincing fat cells to release adiponectin, a protein hormone intimately involved in regulating glucose levels.

PPAR-gamma is also thought to increase mitochondrial fatty acid oxidation, so those little cellular powerhouses use the fat in your body to churn out more energy. One of the main promoters of oxidation in mitochondria is something called UCP2, which is categorized as an “uncoupling protein,” which are energy transporters found in the inner membranes of mitochondria. Anyhow, this study found that fish oil increased the level of UCP2 mRNA expression by 3.85-fold.

In succinct terms, fish oil made the genes for PPAR-gamma and UCP2 take it up a notch, thus increasing energy expenditure.

One potentially negative thing about this increase in PPAR-gamma levels, at least if you’re interested in losing body fat, is that it’s also related to an increase in appetite (although it’s also been shown to decrease appetite in other studies – go figure). And this is exactly what they found in this study. The athletes who took the fish oil experienced increased hunger, particularly for sweets.

This is presumably why omega-3-rich herring and sardines are so often served á la mode. Okay, maybe not.

How to Use This Info

There’s one thing I didn’t mention about the study: fish oil dosage.

Surprisingly, it only took a meager amount of fish oil (compared to some other studies, at least) to bring about this 10.67% increase in resting energy expenditure – just 2 grams a day, of which only 600 milligrams were EPA and DHA (360 milligrams of the former and 240 milligrams of the latter).

I was surprised because it usually takes larger doses of omega-3 fatty acids to achieve other beneficial effects. For instance, most studies that reveal cardiovascular benefits from fish oil used a dosage between 2400 and 3200 combined milligrams of EPA and DHA. In fact, most of the time, when studies fail to show positive effects from fish oil, the culprit is inadequate doses.

You see this in real life, too. Most people just follow label instructions, and if the label says to take one capsule a day, they might be woefully underdosing themselves.

Case in point, the Kirkland brand of fish oils available at Costco only contains a combined 250 milligrams of EPA and DHA per serving, which, while maybe serving your minimum daily omega-3 fatty acids needs, isn’t close to affecting any of the therapeutic, restorative, or metabolism-raising changes you’re likely looking for.

Another reason why some fish oil studies don’t pan out might have to do with using capsules that had a high degree of peroxidation, aka, in laymen’s terms, “spoiling,” which is rampant in the fish oil business.

If the “chain of command” is compromised (the oil is exposed to undue heat or oxygen for anything but a short period of time), free radicals attack the fatty acids, rendering them, at best, ineffective and, at worst, harmful to the human body (higher incidence of heart disease conditions and dementia, among other things).

But, surprise-surprise, the Iranian study showed exciting results on just a duck snort of fish oil, which obviously didn’t contain high levels of peroxidized fatty acids (or it wouldn’t have worked). I suspect using even higher doses of fish oil might elevate the resting energy expenditure of athletes even further, but I’ve no proof of that.

Still, I’ve got faith in the higher-dosage theory, and it sure has been proven in other studies concerning other maladies. These higher doses, along with the peroxidation issue, are why I push Biotest’s Flameout® so hard.

Flameout® has a combined 3,080 mg. of EPA and DHA in each serving. It’s also purified by molecular distillation and stringently tested for PCBs, dioxins, mercury, and other heavy metal contaminants, putting it on par with prescription fish oils. It’s also manufactured and handled with kid gloves, hence no peroxidation problems.

So, if you’re interested in investigating whether fish oil causes you to experience an increase in resting energy expenditure, go ahead and try the low dosage used by the Iranians in their study, but I think you’re more likely to see results if you use the higher dose, highly purified Flameout®.



  1. Sara Moradi, et al., The effect of omega3 fatty acid supplementation on PPAR-gamma and UCP2 expressions, resting energy expenditure, and appetite in athletes, BMC Sports Sci, Med & Rehab, (2021) 13:48.
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