Home Body Building Supplements Does Fish Oil Improve Body Composition? – Supplements and Nutrition – COMMUNITY

Does Fish Oil Improve Body Composition? – Supplements and Nutrition – COMMUNITY

Does Fish Oil Improve Body Composition? – Supplements and Nutrition – COMMUNITY

Omega-3 Fatty Acids, Body Fat, and Muscle

Does fish oil help with fat loss and muscle gains or not? How much do you have to take? We finally have the answer. Check it out.

Follow the science, they say. Sometimes they even scream it. Well, if you’ve followed the science of fish oil supplementation, here’s where you’ve traveled the last twenty years:

  • Fish oil improves body composition. More muscle and less fat! Yay! – Science
  • No wait. Fish oil does NOT improve body composition! Boo! – Also Science
  • Hold on! Fish oil DOES improve body composition! Maybe? – Still Science

We followed the science, but the science was drunk and drifted from one side of the road to the other. Does fish oil (omega-3 fatty acids) shift our body comp in a favorable direction or not?

Let’s jump to the answer:

Yes, it does, if you get enough of it in you and give it enough time to work.

See, all those conflicting studies followed different parameters. Some used mega-doses of fish oil; some used puny doses. Some were very short in duration; others were longer. Some studied overweight people; others looked at gym goers and athletes.

With all such studies, smart folks read past the histrionic headlines and dive deeper. But the latest fish oil study should clear everything up, once and for all.

The New Study

This study is cool because it used high-dose fish and resistance-trained men and women. The participants were divided into two groups:

  • A group taking 4.5 grams per day of fish oil.
  • A placebo group taking 4.5 grams per day of safflower oil.

Both groups used the same 3-day-a-week lifting program for 10 weeks. They followed their usual diets but were asked to eat at least 1 gram of protein per kilogram of body weight per day of protein, which is pretty minimal.

The researchers measured body composition with DEXA and measured everyone’s omega-3 index score. That test let researchers know if they used enough fish oil to get inside the membranes of red blood cells and skeletal muscle cells. In this case, they did.

What Happened? Tell Me, Tell Me!

  • Lean Body Mass: The fish oil takers gained an average of 4 pounds. The placebo group gained 3 pounds.
  • Fat Mass: The fish oil group lost 2 pounds. The placebo group lost nothing.
  • Body Fat Percentage: The fish oil group lost 1.4%. The placebo group lost 0.6%.
  • Maximal Strength – Squat: The fish oil group added an average of 53 pounds. The placebo group added 42 pounds.
  • Maximal Strength – Bench Press: The fish oil group added 24 pounds. The placebo group added 14 pounds.

The fish oil and placebo groups did the same workouts and ate roughly the same foods as they did before the study, but the fish oil group:

  • Gained 1 extra pound of muscle while losing 2 pounds of fat compared to those who didn’t take fish oil.
  • Increased their max squat and bench press by 11 and 10 pounds, respectively, compared to those who didn’t take fish oil.

Well, I’m impressed. Like you, I mainly take fish oil for health, longevity, and cognitive benefits, but if it helps me gain a little more muscle, lose some fat, and bolster strength gains, then I’m definitely not going to skip my daily dose.

And this is where the science gets “drunk.” The researchers here said that most of these improvements were (wait for it) statistically insignificant. Yeah, Mr. Ph.D, without saying you don’t work out, tell me you don’t work out.

In defense of the pencilnecks, this is what they usually say. But they’re also looking at these results through the lens of a 10-week study. You’ll probably keep lifting for longer than 10 weeks, so you’ll keep reaping fish oil’s body composition and strength benefits. Also, an experienced lifter is very happy to lose an extra 2 pounds of fat and build a bonus pound of muscle in just 10 weeks.

Luckily, the scientists also looked at “effect size.” That’s the magnitude of the difference between the two groups. After considering this, they said, “Yeah, okay, fine. That’s actually a whopping difference.” (I may be paraphrasing a little.)

But What If You Take EVEN MORE Fish Oil?

The participants in this study took 4.5 grams of fish oil daily, which required them to swallow 7 capsules of whatever brand they were given. That’s more omega-3s than you find in Target and Wal-Mart brands. But our fish oil supplement, Flameout, has 5.5 grams, and you only need 4 capsules.

Could that extra gram improve these already impressive results? Maybe the next study will test that out. Until then, rest assured that the consistent intake of high-dose, concentrated fish oil (preferably high in DHA) does give you the edge when it comes to body composition. Add that to its long list of benefits.

Note: Shoutout to T Nation contributor Bill Campbell, Ph.D. for pointing out this study in his excellent Body by Science newsletter.




  1. Heileson, et al. The effect of fish oil supplementation on resistance traininginduced adaptations, Journal Of The International Society Of Sports Nutrition, 2023, VOL. 20, NO. 1, 2174704.


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