Do Metabolism Boosting Foods and Supplements Exist? Here’s The Real Story.
As someone who has reviewed pretty much every fad diet and nutrition MLM out there, I’ve seen a lot of metabolism-boosting claims about food.
From celery juice to lemon water to apple cider vinegar to protein shakes, companies never miss an opportunity to tell you that their product can ‘fire up’ metabolism and help you burn fat.
I’ve even seen other RDs in the media saying that chili peppers and cold water can increase metabolic rate. Um. Okay.
But do metabolism-boosting foods really exist? Can we eat a certain food, or take a supplement, and let it do the work for us?
We can’t talk about metabolism-boosting without talking about metabolism itself. Let’s have a brief science lesson to get us going.
Metabolism is the process of converting what we eat and drink into energy. The energy that accounts for what we consider ‘metabolism,’ is divided into four parts:
BMR, or Basal Metabolic Rate. Your BMR is the energy your body expends just to keep you alive. That means, your heart beating, lungs breathing, brain thinking sort of stuff.
NEAT, or Non-Exercise Activity Thermogenesis. This is energy that you expend just going about your business. Walking around, brushing your hair, moving your hands, all of that. It’s the movement that doesn’t include intentional exercise.
EAT, or Exercise Activity Thermogenesis. This is the energy you use during intentional exercise.
TEF, or Thermic Effect of Food. These calorie are used for the digestion of food. Each macronutrient has a different TEF – fat is the lowest, at 0-5% of calories eaten. Protein, on the other hand, is the highest. We expend up to 20% of the calories we eat in protein, just to metabolize it.
This is probably why some people say that protein ‘burns fat,’ which isn’t exactly true.
Here’s the chart I always use to describe the components of metabolism:
Published online 2014 Feb 27. doi: 10.1186/1550-2783-11-7
As you can see, BMR is by far the greatest component of our energy expenditure. This is important, because while small amounts of caloric burn do add up, it’s very tough to change your BMR.
Although so many of us try to burn calories off by exercise, the EAT is actually responsible for a very small part of our energy expenditure.
Metabolism is determined by genetics, as well as age, gender, and muscle mass (FYI: muscle burns around 4 calories more per pound than fat, so not a massive amount). Thyroid hormones can also affect it, as can some medications.
Do some foods raise metabolism?
When someone tells you that a certain food or supplement ‘raises’ or ‘boosts’ metabolism, they mean that it has a positive impact on one of the components we discussed above.
And when you hear someone say it, you should be immediately suspicious.
Some of the most popular ‘metabolism boosting’ foods have absolutely no evidence behind this claim. For example, there is nothing at all about lemon water or vinegar that would suggest that it raises metabolic rate. Not even a little bit.
Saying that those foods can raise metabolism is suggesting a physiologically impossible leap. Like changing a person into a dog, it just can’t happen.
Yet so many people say it does. I’m not sure why.
I’ve seen several dietitians in the media saying that chili pepper raises metabolism. This is a true claim, but unfortunately, it’s only half of the story. Nobody ever tells the other half, which is the most important one.
Some research says that hot peppers raise metabolic rate, but only by a little – like, around 8%, and only for a very short time. The sad thing is that even reputable entities like Penn Medicine, say that spicy foods can ‘kick-start’ your metabolism, even if much of the research has been done in animals and lab dishes.
That’s outrageous. And who wants to pour hot peppers on everything they eat? Is it worth the extra 13 or so calories that you’re maybe going to burn? Ouch.
It’s the same thing with cold water – some people claim that drinking ice cold water can speed up metabolism because your body needs to use calories to warm that water up. Sure, like 3 extra calories…which thanks, but no thanks, aren’t worth freezing all day long for.
Do fat burners work?
Many commercial ‘fat burners’ – like Xyngular’s Accelerate, Plexus Metaburn, Modere Burn, Isagenix Natural Accelerator, and all the ones that every single other nutrition MLM sells, contain some variation of hot pepper, along with chromium (no research that proves it has any fat-burning properties at all), green tea, caffeine, green coffee bean, and/or garcinia (the triumvirate of uselessness).
The truth is that all fat burning supplements are a complete waste of time. Think about it like this: if we could just take a supplement to burn our fat, everyone would be doing it, and far fewer people would be obese.
A legitimate ‘fat burner’ would also not be sold by MLM, it would be regulated by the FDA and used as first-line treatment for anyone who needs to lose weight.
It’s important to note that there is research about many of the ingredients that are supposedly ‘fat burning.’ But the presence of research at all, isn’t an indication that this research proves anything. Much of it is poorly done, old, and unremarkable.
And this goes for anything nutrition-related: I see a lot of ‘proven by scientific research!’ claims that companies are making, but when I go into the actual research, it’s not compelling in the slightest.
Does breakfast boost metabolism?
How about breakfast? Does it really ‘start up’ our metabolism? I’m so glad you asked, because no, it doesn’t.
The research on breakfast – whether it helps with weight loss, whether it makes you smarter, whether or not you should eat it – is notoriously inconclusive. The ‘breakfast revs metabolism’ claim goes along with the ‘not eating breakfast puts you into starvation mode’ – which I covered in this post.
Eating breakfast doesn’t speed up your metabolism, just as much as skipping breakfast doesn’t slow it. We need to stop oversimplifying the human body, and we’re all different. If you’re not a breakfast eater, please don’t feel compelled to start because of ‘fat burning.’
Speaking of eating, let’s talk about protein and metabolism, because this is one thing that deserves a mention.
I said above that protein has the highest thermic effect of food, so yes – technically we do use more calories digesting it than we do for other macronutrients. But this doesn’t really translate into ‘fat burning’ the way you might think. It’s more than you don’t end up with as many calories.
To put it into numbers, if you eat 300 calories worth of protein, you may expend up to 60 calories digesting it. But we’re all different, and while small things do add up, it’s important to not go overboard.
I mean, protein is delicious, and it plays an important role in satiety, variety, and muscle mass maintenance. But eating a ton of it at the expense of other foods just so you ‘burn fat’ is sort of silly. You do need adequate protein (How much protein do you need? I answer all of your protein questions here), but nutrition is a balancing game.
Even though protein is pushed as a metabolism booster, what’s the deal with those metabolism diets that claim to use the right ‘combination’ of foods to speed up metabolism?
I shudder. Seriously, I have seen so much garbage out there, and metabolism diets are definitely in that category.
Let’s get one thing straight right off the bat: there is no secret combination of foods that work synergistically to raise metabolism. That just doesn’t happen. And no matter which day of the week you choose to eat certain things, you can’t ‘trick’ your metabolism into speeding up.
And no, there is no such thing as a ‘metabolic type.’ As in, you’re a different ‘type’ than someone else, and therefore need a different diet (which the person who makes this claim is happy to sell you, of course).
That’s absurd and 100% made up.
Metabolism is complicated. Avoid people and brands who promise that their products can ‘boost’ metabolism, burn fat, and ‘torch calories.’ If we could just pop a pill, drink a shake, or eat a meal and magically speed up our metabolism, we’d be doing it by now.