Where Does Fat Go When We Lose It?

As an American it is nearly impossible to avoid feeling overwhelmed about weight loss, food and diet. We are absolutely inundated with information about supplements, protein shakes, vitamins, ab workouts, love handles, and beer bellies. We are constantly exposed to images of those with God-like physiques and those who could stand to lose a few pounds.

While the question at hand is almost universally "How do I lose weight?", it is so so rare that anyone ever asks "How do I lose weight?"

What does the physical process of weight loss involve? how do our bodies actually expel fat from our bodies when we restrict calories and lead more active lifestyles? Almost everyone knows the basic tenets of weight loss. Consume less calories than you burn. It is a simple physics problem of energy input versus energy output. This is easier said than done, but besides the psychological barriers people face when struggling with weight loss, it is as simple as counting your calories in and keeping them lower than the calories you burn.

So where does the fat that we burn go?

What if I told you that we breathe it out?

You might look at me like I have 3 heads. It sounds not only implausible, but impossible. The idea of breathing out our excess body fat is ridiculous. However insane this idea may sound it is absolutely factual, and backed by years of scientific evidence.

Not only is this idea true, but has been known since the time of Antoine Lavoisier, who lived in 1700's France. He deduced that respiration was a form of combustion just like fire consuming a block of wood. When people say they are going to go burn fat, they are literally burning fat. The food and oxygen we consume is converted in the body into carbon dioxide and water. As science advanced forward, we discovered that out of 10 kilograms of human fat (combined with 29 kilograms of oxygen) 8.4 kilograms of that fat is expelled from the lungs during respiration as Carbon Dioxide, and the rest is released as water vapor, and water in excrement.

It's difficult to comprehend just how much 29 kilograms worth of oxygen is. To put it in perspective, the average human being breathes in about 13 kilograms of air a day, and oxygen only makes up 21 percent of that air. That's only 6.9 kilograms of oxygen daily. it only makes sense that to achieve the right amount of respiration and caloric restriction to lose weight is so difficult given this fundamental equation that requires a full 2.9 kilograms of oxygen per kilogram.

At its simplest level, the fat in our bodies is stored as individual hydrocarbon molecules. All food that we eat at a fundamental level is made of hydrocarbons. When we consume more than we require, our bodies have systems that convert the hydrocarbons into fat that we can store for a later time in case of survival situations with little to no food. When that time comes and we are consuming less than what is necessary to keep us at the same weight, our bodies convert these hydrocarbons into carbon dioxide, and water, and use the energy that is expelled from the release of these hydrocarbons. It is so simple at a base level; hydrocarbons in, hydrocarbons out.

Through all of the common knowledge people seem to have about losing weight, and the level of diet plans people regiment themselves with, one would expect to see a more straight-forward and scientific explanation for how fat physically leaves the body. I personally believe this is a case of truth being stranger than fiction. If more people knew the chemical mechanisms behind how we lose weight, we would have a more healthy and scientifically literate society, and we would learn to appreciate and honor the incredible physical mechanism that is our human body.