First up, let’s set the record straight … Fat is not the enemy. Our bodies need fat for energy and to support cell growth. Fat is what helps protect our organs, keeps us warm, and enables our bodies to absorb nutrients and produce important hormones. We all need fat.
It’s when we have too much fat that it becomes an issue. Excess fat is linked to a raft of health issues and chronic disease. Everything from high blood pressure and heart disease to cancer has been linked to obesity, and every major function in your body is negatively impacted by excess weight.
Add to this modern society’s obsession with the lean and slender aesthetic and it’s no surprise that fat loss is a hot topic. The health and fitness world has become saturated with bronzed-bodied role models and infomercial salespeople offering the latest dietary fads, pills and get-ripped-quick schemes for a fat-free physique.
Surprisingly, then, one of the most obvious questions raised by all this fat-fixating is never really addressed: when it leaves our bodies, where does the fat actually go?
If you’re unsure, you’re not alone. A 2014 study showed that when it comes to fat loss, even health professionals are confused. Out of the 150 doctors, dietitians and personal trainers asked, only three gave the correct answer.
Some believed fat turned into muscle, or that it left the body via the colon, both of which would earn a fail in an exam. Others surveyed believed fat was converted into energy and lost as heat (no doubt based on the ‘energy in equals energy out’ assumption). The trouble is, this would disobey a fundamental law of chemical reactions, known as the conservation of matter (or mass), which states that the same amount of matter comes out of a reaction as goes into it. It doesn’t simply vanish. Put simply, fat tissue is full of lipids – compounds that store energy. Even if those compounds are broken down and generate heat, you’re still left with the same number of atoms you started with.
So, where does the fat go?
The answer is probably happening to you right now. The truth is, fat is converted into carbon dioxide and water. You literally breathe most of it out.
When you begin to run low on fuel you produce a hormone that, when mixed with oxygen, breaks down fat to use its energy. When fat is metabolized, it needs to go somewhere. Once converted to CO2 and water, over 80 percent of each measurement of fat leaves the body as CO2. The rest is released as sweat and urine
This doesn’t mean you can get rid of any unwanted jiggle by simply huffing and puffing on the couch. The only way to consciously increase the amount of fat your body converts to CO2 is by moving your muscles. Simply standing up and getting dressed more than doubles your metabolic rate, so you can only imagine the effect of a good workout. Studies show that the disposal of CO2 is greatly elevated during exercise due to increased breathing and sweating. So a higher intensity workout will produce more huffing and puffing – more energy burned, more converted fat expelled.
Now that you know that fat is actually leaving your body via your lungs, you can use it as great motivation. Next time you gasp your way through your final set of burpees, don’t think of the heavy breathing as a sign of exhaustion, consider it proof that you’re eliminating fat and use it as motivation to keep going.
Another consideration is to think more about how you’re breathing, and add breath training into your routine.
Given the link between breathing and fat loss, it makes sense that becoming a more efficient breather makes you more efficient at burning fat too. While there's no concrete evidence of this, there are several promising studies that link regular breathing exercises with increased weight loss and reduced body fat.
One study found obese individuals who regularly practiced the Senobi breath technique for four weeks experienced a significant reduction in body fat. Another small study found that those who did diaphragmatic breathing exercises had a higher resting metabolic rate, which can lead to increased weight loss. And another 8-week study found that three 45-minute breath training sessions a week significantly reduced body weight and body mass index.
You can learn more about the benefits of breathwork here.