The skinny on capsaicin and increased metabolism

Guess what? You can get SKINNY using only HOT SAUCE!! Yep, it’s proven: if you douse every meal in an ultra-super-spicy sauce, you can lose weight faster than ever before. The secret? Because your food will be too spicy to eat, you’ll reduce your daily caloric intake by 100 percent!

Of course I’m kidding. But sometimes I feel that “health” magazines, blogs and Instagram accounts boast equally ridiculous claims with no intended satire. A quick internet search of spicy food and health rewards you with a slew of articles that  boast various health benefits associated with eating spicy food. By far the biggest (no pun intended) claim is that eating fiery foods will help you lose weight.

While none of the articles I read told me to make my food too spicy too eat, some of the claims I read were almost equally ridiculous.

For example, this article on Self.com stated that adding spice to your meals will increase your metabolism and “burn bonus calories.”

So, is it true that eating spicy food will make you skinny?

Before we delve into that claim, I need to make a caveat: this blog post isn’t so much about a health trend as it is about a “get skinny” myth. In fact, contrary to our society’s obsession with the quest to be thin and lean, losing weight is not inherently healthy. We shouldn’t conflate health claims with fatphobic propaganda that is framed as science.

Nevertheless, I’m sure you’re all curious about whether eating spicy food is likely to help you lose weight or increase your metabolism. Spoiler alert – it won’t to any extravagant degree. But, there is some super interesting science about how spice affects metabolism. Bear with me here!

Capsaicin: the all-powerful molecule

Some people love spice in their food and could chomp down on a raw habanero pepper like it was an apple, while others avoid ground pepper because the hot sensation is all too much for them.

Regardless of where you fall on the spice love train, we all know we all know what it feels like when we eat something super spicy. There is a reason that we call something “hot” when it’s got a kick to it—our mouth feels like it’s on fire, our cheeks turn, red, we might even start sweating.

You can thank a little molecule called capsaicin for the spicy experience. Capsaicin is in all different chillies in different concentrations—the higher quantity of capsaicin, the spicier a chilli will be. You can also thank capsaicin for all of the health claims surrounding spicy food—this little guy is the star of today’s show.

How does one tiny molecule have such a strong reaction in our body? Capsaicin binds to the same receptor that triggers a heat response in our bodies—it’s called the TPRV1 receptor.

What the hot?

To understand the role of a receptor, let’s think of our body as an office building, and the cells are offices with little business people working inside of them. If there is a problem within the company that a specific department needs to take action on, the appropriate office receives an email with instructions on how to proceed.

The receptors on the outside of our cells are like predetermined emails that can be activated by specific conditions.  Some of our receptors are specific to a certain type of cell, but others can send signals to many different types of cells, just like an email regarding a company-wide Christmas party would go out to the entire office.

The TRPV1 receptor is normally triggered by heat. When your body is exposed to high temperatures, a receptor sends an urgent email is sent to the high ups of the company (your brain).  The brain sends a memo to the appropriate workers requesting action to be taken to cool down the system.

This memo goes to many different departments—sweating, vasoldilation (which you can thank for resembling a fiery tomato when you’re too hot), and the urge to jump in a pool of water are all strategies your body’s systems use too cool you down and make sure your cells don’t literally melt.

When we eat spicy food, capsaicin hacks into the network and send out an email saying that our body is too hot. Our body, being a reliable and prompt workforce, then sets out to cool us down—hence the feeling of being “hot” when we eat a habanero pepper.

How does it make you skinny?

What does this have to do with your metabolism and losing weight, then?

The key to this story is that when capsaicin binds to our receptor, the body starts pulling out all the stops in order to cool itself down, but even though we feel hot, we didn’t actually have an excess of heat in the body.

As a result, the body unknowingly cools itself down more than we actually need to—that sneaky capsaicin actually made us colder than we were originally. But not to worry! There is always some incredible supply chain supervisors in our temperature regulation department come in and save the day.

The supervisor cells notice that we are too cold and instruct our cells to generate heat. Our cells can use energy inputs (like a juicy hamburger)  and turn them into heat through an incredibly beautiful and complicated system called non-shivering thermogenesis. This system uses a lot of calories—which means that your burn more energy than you would have if you hadn’t eaten the spicy food in the first place.

What doesn’t add up

So yes, in reality, when you eat spicy food, your body gets momentarily confused and has to use extra energy. But, the key word here is, momentarily.

A group of researchers at Maastricht University in the Netherlands tested this out in humans. They found that people who were given 1 gram of chilli pepper to eat with every meal burned o.7 percent more calories than those who ate no spicy food at all after one day of eating spicy food.

Now, there are so many factors that we must take in to consideration before we can say that spicy food will help you burn “bonus calories”. First, o.7 percent more calories is only about 14 calories a day, or about 10 blueberries.

Also, the extra 0.7 percent of calories used was only observed in participants who were already eating at a caloric deficit, i.e. eating fewer calories than they burn. Participants who ate enough calories a day to maintain their current body weight did not burn any extra calories from eating spicy food.

Most important, I think, is that these participants only ate spicy food for 36 hours. The thing about the body is that it is extraordinarily good at adapting to changes in its environment. That’s probably why other researchers have noticed that people who eat spicy food on a regular basis don’t show any noticeable difference in their metabolism from people who like to keep things bland.

The Verdict

There are many other studies conducted in rats and humans that have looked at the effects of capsaicin on metabolism, and some of them have conflicting results. For the most part, these researchers are trying to better understand the minute workings of energy balance in humans, and they aren’t too concerned about finding a quick weight-loss solution.

My verdict for this one is that our society needs to get away from the idea that skinnier is healthier. As for spicy food, the science of capsaicin is cool, but you aren’t going to lose weight any faster by putting Sriracha on your oatmeal.