Ever wonder if fat burners actually work – or if they’re just expensive caffeine pills wrapped in hype?
If you could read only one research paper to answer that question, this would be it:
“Comparing the effectiveness of fat burners and thermogenic supplements to diet and exercise for weight loss and cardiometabolic health” (Clark et al., 2021), published in the peer-reviewed journal Nutrition and Health.
This was a peer-reviewed scientific report that directly compared popular fat-burning supplements against diet and exercise.
The results were eye-opening.
But you don’t have to read the study, unless you’re a science nerd like me. I can break it down for you in about a 3 minute read, below:
Why This Study Matters
The reason this is so important is that it wasn’t a single study, it was a systematic review and meta-analysis. (A study of studies). This is the strongest type of evidence you can get.
Always remember, it’s often possible to find a single study to support a position or bias, but when you look at the entire body of research on a topic, the truth comes out.
In this case, there were 21 studies on fat burners evaluated. They all had a duration of at least 8 weeks and involved subjects who were overweight.
In these studies, all the usual over-the-counter thermogenic suspects were examined, including green tea, green coffee bean, garcinia, caffeine, capsaicin, L-carnitine, synephrine, ephedra, and ephedrine (technically a drug, and no longer over the counter).
Here was the author’s conclusion:
“There was no indication that fat burners and thermogenic dietary supplements were any more effective than exercise or a combination of diet and exercise.”
The Supplement Industry Doesn’t Want You To Read This
Let’s translate that into plain English.
The claim that fat burners can produce more fat loss than diet, exercise, or the combination of both is nonsense.
Complete nonsense.
And yet how many times have you seen ads that promise for consumables:
“Burn fat without diet or exercise.”
I’ve seen that claim for decades. It’s still everywhere.
According to the Federal Trade Commission, claims like that are illegal. But that doesn’t stop the marketing machine.
Now you might be thinking:
Fine, maybe they don’t work instead of diet and exercise. But what if you add them on top of a solid program? Wouldn’t that give you an edge?
That’s a fair question.
The answer is still no.
Across 21 studies, researchers found either no benefit at all, or such a trivial effect that it doesn’t translate into meaningful fat loss over time.
Not pounds.
Not noticeable body fat reduction.
Not a visible difference in the mirror.
If there are any benefits at all they are trivial and they fade quickly as the body adapts. Plus, so called “fat-burners” do nothing to help you keep weight off after you lose it.
They Don’t Work – And They Are Not Risk-Free
In this study, they also looked at the effect of fat burners on health (cardiometabolic markers such as blood cholesterol and blood pressure). Out of the 21 studies included, 10 of them reported adverse effects. Here’s what the scientists said:
“Changes induced in health status due to supplement use were no better, and somewhat worse, than those induced from exercise or a combination of diet and exercise used for comparison.”
Then they got specific and listed some of the potential dangers:
“We must draw attention to the ever-growing reports of adverse effects and negative outcomes from the use of purported fat burner supplements. This list of adverse outcomes includes Rhabdomyolysis, ischemic stroke, and sudden cardiac death stemming from using these supplements in conjunction with diet and exercise.”
“Additionally are the reports of hepatic and renal issues that are associated with the use of sympathomimetic dietary supplements. More troubling are the reports of psychiatric, cognitive, and sleep disturbances associated with the use of thermogenic substances.”
So, I can summarize like this: Hapless consumers spend 38 billion a year (on all weight loss supplements combined) for somewhere between zero and trivial fat loss benefit, with side effects including potential liver and kidney damage and risk of stroke and death. Sounds awesome. Where do I sign up?
What About Studies That Say They Do Work?
Despite this kind of strong meta evidence, some people are staunch supporters for these supplements and will argue to the death about it.
Sometimes that’s because occasionally a study comes along suggesting they do work. Like this one
A study in the scientific journal Nutrients (Siedler 2023) appeared to show that a multi-ingredient over the counter fat burner actually did have a thermogenic effect. Specifically, there was a 112 calorie per day increase in energy expenditure. This one made the rounds for months in the news and across social media.
I read the study – the whole paper – and in an ironic twist, it turns out that while it’s true there was a minor thermogenic effect, at the end of the study there was zero change in body composition. This is most likely due to building tolerance over time and also due to compensation. (When energy expenditure goes up, most people compensate by eating more later).
In addition, there was zero change in eating behaviors (the product didn’t suppress appetite as advertised).
It’s your money, but my advice is to save it. Fat burners are a waste.
Train hard and expect success!
– Tom Venuto,
Author, Burn the Fat, Feed the Muscle
Founder, Burn The Fat Inner Circle,
PS. So what does work? Glad you asked. An-all natural fat loss program with an almost quarter century track record of success from someone who doesn’t sells supplements, like Burn the Fat, Feed the Muscle (click here).
About Tom Venuto
Tom Venuto is a natural bodybuilding and fat loss expert. He is also a recipe creator specializing in fat-burning, muscle-building cooking. Tom is a former competitive bodybuilder and today works as a full-time fitness coach, writer, blogger, and author. In his spare time, he is an avid outdoor enthusiast and backpacker. His book, Burn The Fat, Feed The Muscle is an international bestseller, first as an ebook and now as a hardcover and audiobook. The Body Fat Solution, Tom’s book about emotional eating and long-term weight maintenance, was an Oprah Magazine and Men’s Fitness Magazine pick. Tom is also the founder of Burn The Fat Inner Circle – a fitness support community with over 52,000 members worldwide since 2006. Click here for membership details
Scientific References:
Clark J, et al, Comparing effectiveness of fat burners and thermogenic supplements to diet and exercise for weight loss and cardiometabolic health; systematic review and meta-analysis, Nutr Health, 27:4, 445-459, 2021.
Siedler M, et al, Nutrients, Chronic thermogenic dietary supplement consumption: Effects on body composition, anthropometrics, and metabolism, 15:4806, 2023
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