Will green coffee beans help with weight loss?


Happy new year!

To start 2019, I’m going to dig back a little and find an oldie but a goodie. And there’s a valuable lesson we can learn from it as we go into the new year. You’ll get that lesson only when you get to the end.

Green coffee beans and the various versions they come in had become the hot new weight loss supplement that’s in everyone’s cups and on everyone’s lips after celebrity television doctor, Dr Oz, called green coffee a “miracle pill” and then got shamed in front of the US Congress for saying so. But green coffee beans just don’t seem to go away! But does it work? Let’s dip into this craze and see what makes it tick.

Where it all began

Back in 2011, a review stated that green coffee extract could help in weight loss but also noted that the studies it analysed were small, short term. In other words, they just didn’t have enough information to prove this was not only an aberration.

In 2012, Dr Mehmet Oz, also called Dr Oz, featured green coffee beans on his television show. He went gaga (not the lady or the radio) over it and called its effects “magic” and “staggering” and all sorts of other gushy things. Needless to say, his following, which is immense, bought into it with no problem whatsoever.

I digress a bit. But to make a point.

To be honest, I once bought into his spiel too. I had only just heard of him, because he was talking about white kidney bean extract as a supplement that stopped your digestive system from absorbing carbs, (otherwise called a carb-blocker) which helps if you’re on a low carb diet. Now, before you go out and buy yourself a bottle of the stuff, read the rest of my story.

So here I see a qualified medical doctor, a reasonably successful cardiac surgeon, in fact, talking about a supplement on TV. Now, most of us respect doctors and the advice they give. After all, they are decidedly more educated than us on the topic of health and medicine. I am no different. I went and got myself a bottle.

Later, I discovered that this white kidney bean extract wasn’t quite as magical as Dr Oz said it was. It apparently had an effect in clinical trials but very inconsistently. Definitely not enough to justify the cost. You can possibly gain similar benefits from adding any regular legumes to your diet.

That gave a double take. Then I watched a few episodes of Oz's show, which used to be played quite late at night. Some advice he gave seemed legit, and some were actually troubling. Like the time he said a traditional Chinese medicine nasal spray worked better than the stuff you get at the pharmacist. Which is weird since Chinese traditional medicine isn’t very reliable. And the deeper I dug, the more I found out how much nonsense Dr Oz peddled to keep his ratings up and the money flowing in.

And then, this happened.

Dr Oz gets caught

In June 2014, Dr Oz was called in front of the US Senate for a hearing. I was blown away as he stammered and stumbled through his testimony, openly admitting that some of the things he promotes on his show “don’t have the scientific muster to present as fact, but nevertheless, I would give my audience the advice I give my family all the time, and I have given my family these products.” Yes. He said those exact words.

If he was wrong about this, what else could he be wrong about? Apparently a lot.

As for the green coffee bean extract, here’s his exchange with Senator McCaskill:

“Dr Oz: Well, if I could disagree about whether they work or not, and I’ll move on to the issue of the words that I used. And just with regards to whether they work or not, take green coffee bean extract as an example. Uh, I’m not gonna argue that it would pass FDA muster if it was a pharmaceutical drug seeking approval, but among the natural products that are out there, this is a product that has several clinical trials. There was one large one, a very good quality one, that was done the year that we talked about this, in 2012. Listen, I’ve…

Sen. McCaskill: wh..wha..I wanna know about that clinical trial. Because the only one I know was sixteen people in India that was paid for by the company that, that was in fact, at the point in time when you initially talked about this being a miracle, the only study that was out there was the one with sixteen people in India that was written up by somebody that was being paid by the company that was producing it.”

Yup. So Dr Oz is full of crap. Notice how he’s just dodging and telling flat out lies about the “research”? He got demolished! You will be wise to steer clear of anything he has to say about anything. Even if he says something that’s legit, there’s no knowing what kind of crap he will try to sell you the very next second.

Now, Back to the Coffee

The bottom line about the coffee is that there is absolutely no evidence whatsoever to show that it has any benefits at all.

Dr Oz based his entire spiel on a lame study called the Vinson Trial which has since been retracted. Scott Gavura, writing for Science-Based Medicine described it like this:

“All we could conclude from the Vinson trial was that it was poorly conducted, sloppily written and provided unimpressive and clinically-useless results. There was no convincing evidence to suggest that GCB [green coffee beans] offered any meaningful benefit. As I noted in my conclusion at the time, GCB had all the features of a bogus weight loss product. It was implausible and backed by flimsy evidence with some serious methodological issues. Even before we knew it was fraudulent, it was clear this trial should not be used to guide treatment decisions.”


So do green coffee beans work after all? The answer is...kinda. There was a systematic review of all the studies done on green coffee bean extract and it is inconclusive. The studies it reviewed were small, short and some had serious methodological flaws in them. The result: GCB extract does seem to promote weight loss, but it doesn’t seem to be much, and we just can’t be sure of the long term effects or even side effects.

So, if you want to lose weight, this just isn’t worth the uncertainty or your money. You will be much better off just cutting 300-500 calories off your daily consumption, burning more calories by doing resistance training and leading a more active life.

Critical Tools

I’m introducing a new section here to describe the critical thinking tools I used to find the facts behind this fad supplement. I’ll be updating all my past posts with this new section so you can get a clear view of what needs to be done to sniff out a scam.

  1. Find the origin. I looked back at GCBs and found Dr Oz

  2. Is the source reliable? Dr Oz definitely didn’t turn out to be a reliable source. The reliable sources I found that most scientists seem to agree with are linked in this post.

  3. Does science agree with it? The most reliable standard of research is the systematic review or meta-analysis, which takes all the studies done about one subject and puts them together to find patterns and reliable data. The systematic review done on GCBs casts doubt on its effectiveness.

So what’s the lesson for the new year?

Don’t buy pills from snake oil salesmen that pretend to be doctors wearing lab coats or scrubs.

Do you think green coffee works? Have you ever fallen for Dr Oz's spiel like I did? Let me know in the comments.