Conjugated linoleic acid (CLA for short) is often hyped as a “fat burner”, but research tells us this is absolute bullshit.
In fact, some of the claims being made about what CLA can supposedly do are outright ridiculous. For example, several supplement companies suggest that it can specifically target body fat stores around the abdomen.
(And yes, there’s trainers out there saying this who should know better!)
Let’s take a deep dive into the research on this supplement, to see what it’s really capable of.
What Is Conjugated Linoleic Acid?
CLA is a dietary fat which belongs to the Omega-6 family.
You’ll find it in foods like beef and milk, and it can also be used as a supplement (a clinical dose is 6g-9g per day).
Supplement manufacturers claim that CLA can inhibit the production of lipoprotein lipase (LPL), which is an enzyme responsible for telling our fat cells to soak up fat from the bloodstream. They theorize that reducing LPL means more fat is being burned for fuel instead of stored in your fat cells.
If this theory was correct it would make CLA a fucking awesome supplement.
It would also make it a good muscle building supplement, too, because if we were burning dietary fat for fuel this would enable us to hang on to our lean muscle tissue more easily.
Don’t Believe The Hype
I’d love it if CLA was as good as it claimed to be.
Let’s face it, if there was a supplement which could encourage your body to burn fat and help it retain lean muscle, I think we’d all buy it.
Unfortunately, all is not what it seems.
In some ways, the research on CLA reminds me of Rocky V.
You see, it’s a movie which starts off quite nicely (much like the animal-based trials conducted for CLA back in the day), and then Tommy Gunn is introduced (human trials) and the whole thing becomes a fucktacular shitnado of ass.
Every single study which shows a positive fat burning result (e.g. the same studies which supplement manufacturers love to cite on their packaging) came from animal trials, and the results are nowhere near as good in human trials. There re only two human trials (ever!) which show positive results, and both of those studies were questionable, because the first allowed participants to self-report their calorie intake (notorious for its inaccuracy) and the second didn’t track any calories at all (seriously!). Quite frankly, you can put those studies straight in the bin! (1, 2, 3, 4)
Every other study involving humans showed that CLA is an ineffective fat burner. (5, 6, 7, 8, 9)
And to drive the final nail into the coffin, let’s look at the findings of a 2012 meta-analysis which is considered the most comprehensive overview on CLA supplementation ever:
“Of the 3095 articles initially retrieved, only 32 studies were eligible for this meta-analysis. This is because the bulk of data surrounding CLA comes from poorly conducted trials which suffered from either flawed methodology or confirmation bias.
The data shows that CLA (either obtained through dietary intake or in supplement form) does not have a positive impact on fasting blood glucose nor waist circumference.” (10)
Russ’ Rating
CLA cannot live up to its own hype.
The outlandish claims being made by supplement manufacturers (not just about weight loss, but also its ability to target fat stored around the abdomen) are not supported by science.
If that ever changes I’ll update this article, but until that day, remember that anyone telling you about the fat loss benefits of CLA is probably just trying to sell it.
Further Reading:
If you enjoyed this blog, then you’ll probably also like reading these.
>> Russ’ Guide To Supplements
>> Behold, The Alpha Omegas!
>> How To Get In Photoshoot Shape In 2 Months
References:
- Ostrowska E., et al. Conjugated linoleic acid decreases fat accretion in pigs: evaluation by dual-energy X-ray absorptiometry. Br J Nutr (2003).
- Moya-Camarena S. Y., et al. Conjugated linoleic acid is a potent naturally occurring ligand and activator of PPARalpha. J Lipid Res (1999).
- Watras A. C., et al. The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain. Int J Obes (Lond) (2007).
- Chen S, et al. Effect of conjugated linoleic acid supplementation on weight loss and body fat composition in a Chinese population. Nutrition (2012).
- Sneddon A. A., et al. Effect of a conjugated linoleic acid and omega-3 fatty acid mixture on body composition and adiponectin. Obesity (Silver Spring) (2008).
- Joseph S. V., et al. Conjugated linoleic acid supplementation for 8 weeks does not affect body composition, lipid profile, or safety biomarkers in overweight, hyperlipidemic men. J Nutr (2011).
- Riserus U., et al. Effects of cis-9,trans-11 conjugated linoleic acid supplementation on insulin sensitivity, lipid peroxidation, and proinflammatory markers in obese men. Am J Clin Nutr (2004).
- Onakpoya I. J., et al. The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: a systematic review and meta-analysis of randomized clinical trials. Eur J Nutr (2012).
- Navarro V., et al. The body fat-lowering effect of conjugated linoleic acid: a comparison between animal and human studies. J Physiol Biochem (2006).
- Rahbar A. R., et al. Effect of Conjugated Linoleic Acid as a Supplement or Enrichment in Foods on Blood Glucose and Waist Circumference in Humans: A Metaanalysis. Endocr Metab Immune Disord Drug Targets (2017).