No, coffee cannot really help you lose weight, do not believe the hype

Can coffee really help you lose weight by making your fat tissues burn fat (facts vs hype)

The study: “Caffeine exposure induces browning features in adipose tissue in vitro and in vivo“

A study made the news yesterday (24th June 2019) reporting that coffee could help you lose fat by kickstarting a process called thermogenesis in humans.

Thermogenesis is basically the process of burning fat in one of two special types of fat tissue called ‘brown fat’ and ‘beige fat’.

But what is brown fat and what in God’s name is beige fat? And did you know that there is also a thing called white fat?

Georgios Tzenichristos, a nutritionist and fat/cellulite specialist at the LipoTherapeia clinic in London has followed the subject of thermogenesis for the last 20 years and explains:

White fat (white adipose tissue)

White fat tissue is the vanilla variety of fat tissue, the stuff we all love to hate, the one that makes us, well, fat. White fat’s main purpose is to store fat in our bodies for use on a rainy day. It also produces loads of hormones and other chemicals called cytokines, which are implicated in heart disease and diabetes.

So reducing white fat, or at least reducing some of the cytokines it produces is a big deal, not just for aesthetics but for health reasons as well.

Brown fat (brown adipose tissue)

In contrast, brown fat, the stuff mentioned in the study, is a type of fat tissue whose sole purpose is to burn fat for heat creation, i.e. to keep us warm.

Brown fat thermogenesis works amazingly well in mice, which have plenty of brown fat to keep them warm. And they can always readily convert plenty of their white fat into beige fat too, given the right circumstances (think of extreme cold or scientists feeding them stimulants, hot chilli powder or natural supplements at 1000x the normal dose - stuff like that). Mice love thermogenesis and do well at burning fat for heat.

Brown fat sounds like such an amazing idea. Creating lots of brown fat on humans has been the holy grail of weight loss for more than two decades.

Imagine if we could find a way to develop brown fat tissue in our body and then we can eat anything we want and just burn it to heat our body. In this way we could kill two birds with one stone: stay slim and reduce our energy bills. (Not a good idea for those who live in places like Dubai, Texas or Africa, of course, who’s aircondition bills would skyrocket...)

One small detail: unlike mice, adult humans have very little brown fat. Babies have somewhat more brown fat to help them keep warm, but in just a few months they replace it with white fat and they start keeping warm via shivering thermogenesis, i.e. they create heat, like all us adults, by muscle contractions (shivering).

But despite this very small setback, there is still hope. Enter beige fat.

Beige fat (beige adipose tissue)

Now beige fat, is something like a cross breed between white fat and brown fat, hence the name.

Beige fat tissue always starts its life as white fat and then, with the right stimulation (cold, stimulants, hot chilli powder, overdosing on specific supplements, you get the drift), it becomes burning fat for heat, like brown fat tissue does.

There is a small detail here too: beige fat never commits to becoming brown fat. As soon as the stimulation ends, it reverts from what scientists call the “beige adipose tissue phenotype” back to the good old “white adipose tissue phenotype”. In plain English this means that it becomes again good old white fat tissue, which starts storing fat again with wild abandon.

Thermogenesis in humans

And those two facts, the fact that you have very little brown fat on you and the fact that beige fat is very fickle and therefore not worth converting to, are the reasons why you have never heard about thermogenesis before. Because it is a pain to start and to maintain and then, when you stop trying, it just switches off and leaves you cold.

Thermogenesis with ephedrine

In the past, people tried to make their fat tissue burn fat with a weak analog of amphetamine, derived from the ephedra plant, called ephedrine. In fact they used to combine ephedrine with caffeine and aspirin for best results, the legendary “ECA stack”.

Ephedrine indeed helped people lose weight with beige fat thermogenesis. But it also gave them the unwelcome gifts of jitters, palpitations, adrenal exhaustion and other nice side effects.

And when they stopped taking it, their beige fat turned back into white and they started putting on weight like never before, partially due to the adrenal exhaustion. Ephedrine thermogenesis sucks. No wonder it was banned in 2003.

Are you starting to see why thermogenesis is not that popular? I mean, who wants high blood pressure, jitters and palpitations to lose weight? (Some do, I know, the desperate and those who do not respect their body and their health.)

Thermogenesis with ephedrine gives me the jitters.

Thermogenesis with cold

Fast-forward fifteen years after the ‘ephedra years’ and you find people talking about living in cold conditions, permanently, to keep the weight off.

I say permanently, because as soon as you start living like a normal human being with adequate central heating, the energetic but fickle beige fat cells become slobby white fat cells again and it is game over for the “cold induced thermogenesis”.

Another option is, of course, to have daily or twice daily cold showers or dip into a bathtub filled with cold water and ice cubes. Try to convince anyone except the very hard core, superfit people (who don’t need thermogenesis-induced weight loss in the first place) to do that in the middle of the winter. Between getting pneumonia and being overweight, can I please stay overweight please?

Needless to say that those “thermogenic” one-week spa breaks in Italy and France with a bit of cold showers and cold baths thrown in here and there are a joke. After the “thermogenic” week and just about your fat cells decide to take the plunge and become beige you come back home and nothing happens.

Those spas are marvellous places though. People are nice, the massages are great and the food is to die for. Just don’t expect your fat cells to become fat burning furnaces any time soon. Go there for the pampering, the luxury and the sweet illusion…

Thermogenesis with cold gives me the shivers.

Thermogenesis with exercise

Some other people have decided that it is much better to have “exercise induced thermogenesis” instead. This involves exercising like crazy, which in turn boosts the levels of norepinephrine in their bodies, which in return boosts beige adipose tissue thermogenesis.

That’s great, but doesn’t it sound like the age old mantra “do loads of exercise to lose weight”? Who cares if fat is burned in muscles, like we used to believe, or if some of it gets burned in beige fat, like we have recently found out. Finding out that if you exercise a lot and at high intensities you lose weight is not such a great discovery.

Again, like in all the previous applications of thermogenesis, when you stop stimulating thermogenesis, it stops. So exercise-induced weight loss, thermogenesis or not, evaporates into thin air as soon as you stop exercising. Not very surprising, is it?

Now it doesn’t take a genius to realise that people who clock twenty half-marathons a year are not the ones who care about weight loss with thermogenesis. The overweight ones care, and those ones will not be very thrilled to find out that “you know, if you exercise like crazy you can turn your fat cells beige and they will burn fat”. No sh*t Sherlock.

Everyone knows that you burn fat with high intensity exercise. Who cares if fat burning occurs in muscles or in ‘beige fat’?

It gets even worse, thermogenesis with exercise in the cold

As I made it clear before, it is the overweight people who care about losing weight. A super fit person who can exercise at high intensity for two hours in extreme cold is not the target group intended to benefit from this.

So we are entering the realm of adventure sports here. If one can run naked in the snow, complete with GoPro-enabled live footage straight onto YouTube for their fans, that’s good for them, but it does not solve the obesity epidemic.

Thermogenesis with exercise in the cold leaves me cold.

Thermogenesis with capsaicin

If cold can make you burn fat, how about the opposite, perhaps something that really burns? Capsaicin, the active ingredient in hot chilli peppers, was found to also stimulate thermogenesis. So how about taking capsaicin capsules or simply having a big bunch of hot chilli peppers for brekkie? Sounds like a good idea to lose weight?

Great! Now to lose weight with this ‘newfangled thermogenesis thing’, you must endure the runs, feel your back passage burning for months and end up develop hemorrhoids in the process. Doesn’t sound very promising to me.

Thermogenesis with capsaicin gives me the runs.

Thermogenesis with DNP (dinitrophenol)

Now if you are really stupid, you will go for the real deal, the royal road to thermogenesis. Drum roll and enter DNP.

Dinitrophenol (DNP) is a small, simple molecule that creates so much thermogenesis that can, almost literally, fry your organs from within. You take the (banned) DNP pill, and you can be rest assured you will cause so much thermogenesis in your body that you will sweat. Profusely. And, if you don’t die or fry your organs from within and then die, you will indeed lose weight.

With DNP, cells all over your body, not just beige fat cells, burn so much fat that they release so many free radicals that actually cause organ damage. Plus, as cells use up all the energy for heat, they have no energy for the vital processes they should perform, which also contributes to organ failure.

DON’T DO IT AT HOME, or anywhere else for that matter.

Thermogenesis with DNP is deadly.

Thermogenesis with green tea, resveratrol, curcumin and other herbal extracts

Around the time of the ECA stack, mentioned above, world got around that green tea thermogenic and people started using it together with the ECA stack or together with caffeine.

We are not talking about a cuppa of green tea here or a hipster matcha tea ceremony, such as the ones you see on Instagram. We are talking about highly concentrated green tea extracts, equivalent to fifteen or more cups of tea a day. As expected, the liver of some of those people did not warm up to the idea, regardless of thermogenic benefits, so the idea never caught on.

The same applies to other, equally healthful compounds such as resveratrol, curcumin, berberine, quercetin and many others. But although those natural compounds have numerous health benefits in normal or high doses, to get any decent thermogenic effect out of them you need to use monstrously high quantities, which are only possible by force-feeding mice for experimental purposes. For example this very comprehensive review mentions:

“High doses of resveratrol (∼400 mg/kg body weight) have been shown to reduce weight gain in high fat fed-fed mice, in association with decreases in visceral fat pad weight and smaller adipocytes in epididymal white adipose tissue”.

Two points here: firstly, men are not mice. And secondly, 400 mg/kg of body weight is translated into 24,000 mg of resveratrol for the average 60 kg woman, equivalent to, wait for it, 49,200 glasses of wine. Every day. I rest my case.

(*a person taking one 20-mg resveratrol supplement may ingest the equivalent amount of resveratrol found in 41 glasses of red wine, as the good people at Life Extension Foundation tell us).

Thermogenesis with supplements makes my liver swollen.

Thermogenesis with caffeine

And here we are, 24th of June 2019, and caffeine is said to be the hot new way to set your fat on fire.

I’m sure you can sense my drift here. Caffeine is yet another hard-core compound, similar to ephedrine and capsaicin. You can’t have a lot of it to make a real difference in your weight without developing side-effects.

Also, if caffeine, consumed by billions of people around the world, could make people lose weight, via thermogenesis or any other method, they would know it already and everyone would be on it. Some studies found a minor benefit, but it is just that, minor.

As another writer states: “Chances are coffee is not going to turn out to be the weight loss miracle and the answer to the obesity epidemic. Otherwise, we would have probably seen more impact on the epidemic already. After all, as an article in the HuffPost indicated, Americans lead the world in coffee consumption, drinking over 400 million cups a day, yet have the twelfth highest obesity rate, according to the CIA World FactBook.”

However, this new study, published at the journal Scientific Reports by researchers at the University of Nottingham (Caffeine exposure induces browning features in adipose tissue in vitro and in vivo), has found that caffeine does indeed stimulate thermogenesis in humans and that it also stimulates the conversion of white fat cells into beige ones, in both mice and humans.

The researchers used new methodology to prove that temperature on the teeny-weeny little fat we have on our neck indeed rises by about half a degree Celsius (~33.8ºC to ~34.3ºC on the spot tested) after one cup of instant coffee containing 65mg of caffeine - a moderate dose indeed.

So perhaps a higher dose, such as the 400mg of caffeine contained in two energy drinks or in four cups of espresso, would have better results, right? What about ten cups of coffee, for even faster weight loss? Or twenty for extreme weight loss?

The problem is that overdosing on caffeine is not a benign thing. It can give people palpitations, cause anxiety attacks, high blood pressure, high heart rate, diarrhoea and leave the adrenals exhausted after continued use. And when you stop overdosing on it, it will just stop working. That beige fat tissue does not stay beige forever.

On the other hand, with low doses don’t expect much fat burning to occur, otherwise all these moderate coffee consumers (1-4 cups a day) would already be slim - or at least slimmer than their non-coffee drinking peers. And there is no evidence of any significant difference in that respect.

Thermogenesis with caffeine gives me palpitations.

What does the future hold for weight loss with thermogenesis?

Still the researchers are upbeat. They want to find if specific nutrients, perhaps more benign than caffeine and capsaicin, can help switch on thermogenesis. With their new experimental design (first you do in-vitro tests on cells and then you do in-vivo tests on humans) they could screen a few hundred promising compounds, perhaps the ones that already stimulate thermogenesis on mice.

In this way, they can perhaps find the top ten most thermogenic compounds, create a combined pill and make us all lean, mean, overheated machines and help solve the obesity and diabetes crisis.

It is indeed a noble cause and even if it doesn’t bear fruits, it will contribute to our knowledge of thermogenesis, human adipose tissue, diabetes, overweight and obesity. But I am not that optimistic about amazing results any time soon.

The problem is that the known thermogenic compounds must be used at 100x, or even 1000x, times their natural concentration in foods, if they are to make any discernible difference in terms of thermogenesis. At these doses there are plenty of side effects of all kinds, plus we are talking about consuming 10-20 capsules a day. It works on mice in the lab fed by force and not being able to complain, but it is a totally different thing on humans.

Let’s face is, thermogenesis as it stands today is not very practical, not very effective and not very pleasant either. Let’s hope that the nice people at the University of Nottingham can change this one day.

For the last 20 years thermogenesis has left me disappointed.


Georgios is the director of LipoTherapeia, the only aesthetic practice in London specialising in skin tightening and cellulite reduction (, 0207 118 2014). Georgios can be contacted at