Why Fat Takes Longer to Exit the Body

Whether you need to lose a few pounds or need a complete lifestyle change, you’ve probably wondered why fat is so hard to get rid of. Why doesn’t fat simply burn off and exit the body? After all, if we don’t need it all, it should pass right through, right?

Well, understanding how our bodies handle fats in general will help you get a better understanding of how you have to diet and exercise in order to lose those stubborn pounds.

Fats and lipids we ingest are very complex compounds. Found in various cooking oils and other forms of fat we ingest, fats are, pound for pound, the most energy-dense compounds out there. Comprised of carbon, hydrogen and oxygen, they’re harder to break down in our gastrointestinal tract than other compounds, and you know the old saying about oil and water not mixing – fats aren’t dissolving in liquid without some serious help.

The body is capable of easily breaking down carbs and proteins. When it comes to fats, however, we’re dealing with another monster entirely.

How the Digestive System Works with Fat

In general, the human stomach is an awesome thing. Capable of holding nearly 3 pints of liquid, the acid in your stomach will literally dissolve metal. In fact, your stomach acid is so powerful that it eats itself. Over half a million stomach-lining cells are replaced inside of your body every single minute, and the stomachs entire lining will change completely every three days. Lucky you don’t have to feel that!

When fats enter into the stomach, they need some extra help to break them down into water soluble nutrients the cells in your body can handle. Bile is secreted by the gall bladder and the small intestine helps out with lipase. These substances break fats down into fatty acids, emulsifying lumps of fat until tiny fat droplets are left. Lipase, a powerful enzyme, then breaks down these droplets further into fatty acids and glycerol.

Because of the outside help needed from the gall bladder, small intestine and the pancreas (also the home of lipase), you can tell that fats are hard to break down.

How Fat Works in the Bloodstream

The aforementioned process, although relatively slow by digestion standards, only takes around 10 to 15 minutes before the fat is ready to be absorbed into the body via the small intestine. Once the fat is there, blood and lymph vessels absorb it further into the lymphatic system and then it drains into the bloodstream.
Now, there are really only two ways it’s going to work out for fat on this arduous journey: 1) it’s going to be used directly for energy and be oxidized or 2) it’s going to be stored in the fatty adipose cells and pile up with the rest of the stored fat.
Unfortunately, your body would rather burn glucose (sugars, carbs) than burn fat for energy. It’s just how we’ve naturally evolved. So your body only converts about 5% of that fat into glucose to be used as energy, leaving the other 95% (approximately) to be stored as fat.

Why Fat is Stored

Another big question many people ask: Why is fat stored as opposed to simply leaving the body as waste? Again, we’re looking at evolution as the culprit here.

Our lives rising to bipedal animals and building civilizations wasn’t always as convenient as it is today. Even when we were small mammals, millions and millions of years ago, we needed energy reserves. Without a fast food restaurant around every corner, you may have gone a while without the necessary energy needed.

To put it simply, fat is stored as an energy reserve, and that’s why it’s stubborn to leave. It also gathers around delicate internal organs in order to protect against trauma.

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