Dispelling nutrition myths, ranting, and occasionally, raving

5 ways fish oil supplements (probably won’t) help fat loss



A friend recently suggested that I blog about this post touting the five ways that fish oil supplements help fat loss. Of course, the post contains no references for any of the claims so I had to do a little digging and guess at what the existing research supporting them might be. Here’s what I came up with:

  1. “They stimulate secretion of leptin, one of the hormones that decreases our appetite and promotes fat burning.”

The majority of studies I can find regarding fish oil and leptin involve mice, rats, or patients suffering from pancreatic cancer cachexia. Not exactly the general population. Off to examine.com where they reviewed two studies involving fish oil supplementation for women who were over weight. Neither study showed a significant influence of supplementation on serum leptin.

2. “They help us burn fat by activating the fat burning metabolic pathways in our liver.”

Back to examine.com (why do the work of slogging through google scholar when they’ve done it for me?). They found one study that showed no effect on metabolic rate as a result of fish oil metabolism.

3. “Fish oils encourage storage of carbs as glycogen (an energy source in our liver and muscles) rather than fat.”

Examine.com found one study that showed a very slight increase in fat oxidation with fish oil supplementation. Before you get too excited though, the study (the same as was noted in the response to “reason” number two above) participants were six lean and healthy young men. Probably not the population who is interested in taking fish oil for weight loss.

4. “They are natural anti-inflammatory agents. Inflammation causes weight gain and can prevent fat loss by interfering with our fat burning pathways in the liver and muscle cells.”

There were a lot more studies (17 to be precise) looking at this topic that were reviewed on examine.com. The results were a mixed bag. A few found a very small reduction in inflammatory markers in subjects taking fish oil supplements. However, most of the studies found no effect on inflammatory cytokines and it’s important to note that even if fish oil supplements do reduce inflammation in some individuals, we can’t be certain that this will lead to weight loss.

5. “They possess documented insulin-sensitizing effects.”

Examine.com looked at 12 studies and stated that the scientific consensus is 100% that fish oil supplementation has no effect on insulin sensitivity. There are, however, a few studies that have shown an increase in insulin sensitivity but also a few that have shown a decrease in insulin sensitivity.

Overall, there is no evidence to support the use of fish oil supplementation to lose weight. Of course, Dr. Natasha would want you to believe otherwise as the purchase of her fish oil supplements is an “essential component” of her “Hormone Diet”. Remember, it’s a red flag when someone is trying to sell you a quick fix.

Don’t forget, the best way you can get fish oil is to eat fish.

Author: Diana

I'm a registered dietitian from Nova Scotia, living and working in Ontario, Canada. My goal is to help people see food and nutrition from a different perspective and understand that nutrition and health are not necessarily a result of personal choice.

10 thoughts on “5 ways fish oil supplements (probably won’t) help fat loss

  1. This for sure! There’s so much advertising out there with the aim to catch people who are trying to be healthy and if people don’t know how to evaluate what they’re looking at it could definitely result in more than a few problems!


  2. I would consult with a dietician or nutritionist because the amount of fish oil in a capsule would equate to us eating about a hundred fish per day


    • I’m not sure how you came by this information but an average 3 oz serving of salmon contains around 1000-1500 mg of omega-3. Most single fish oil capsules contain less than this.

      I do agree that consulting with a dietitian, pharmacist, or physician before taking any supplement is a good idea.

      Liked by 1 person

      • Oh really? The fish oils I take contain 6000 mg per daily serving. The dietician was telling me that its actually best not to eat too much salmon since they contain a lot of free radicals which speeds up our aging process.


      • Wow! That’s a lot, even if it’s 6000 mg of fish oil, not omega-3. I generally think it’s best to get nutrients from whole foods. However, if you are taking a fish oil supplement usually companies will recommend higher doses than necessary for healthy individuals as they want to sell more. I wouldn’t worry too much about free radicals in salmon.

        Liked by 1 person

      • I’ve seen it help lot of family members lower their cholesterol since it breaks down the fat in their arteries. Also nutrients from whole foods these days dont provide as much nutrients that they did years ago. So we’ll see apples on the market that are twice the size of our fists when it should be smaller. Howcome you wouldn’t recommend worrying about free radicals?


      • The benefits of eating fish likely outweigh any negative effect of free radicals.


      • Our body actually needs supplements to outweigh the free radicals. Since salmon contain free radicals already. It’s the smaller fish that are found at the bottom of the ocean that are ideal to eat because they’re not exposed to as much pollutants


      • All foods contain free radicals to some extent. Evidence is starting to indicate that antioxidant supplements once thought to combat free radicals probably cause more harm than good. Unless you’re eating rancid salmon or taking rancid fish oil supplements, free radicals should not pose a significant issue.

        The smaller fish contain fewer environmental contaminants (such as mercury and PCPs) than do larger predatory fish such as swordfish and tuna.

        I hope that helps clarify things a bit!

        Liked by 1 person

      • Oh yes, i was taught that a few years ago. Thats one of the reasons why i started taking supplements. But wow I’m surprised about the evidence on free radicals. The most powerful antioxidant that I’ve tried is the Isotonix opc3 with pycnogenol. It helped my family and friends with their inflammation, allergies and all sorts of health issues. Even doctors stand by the R&D. But I guess it definitely depends on the products on the market. Most are sold because it’s trending. So companies who didn’t intialy start manufacturing supplements are wanting to inves in the industry because its profitable. But thanks for the info!


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