How does Fat Loss Actually Happen ?

Noticed that people with careers related to medicine or biology tend to be leaner? Understanding how fat is stored and burned by the body makes it much easier to know how to control our body fat levels.

Of course, it’s a very complex process and most of us don’t have the time or inclination to take a degree in human biology just to be lean. But that’s OK, you don’t need to understand it on a super-deep level, just the basic principles will be helpful enough.

The problem is, it’s rare to find an article which explains them in a way most ordinary people can understand… So, I guess it’s down to me!

Here goes!

How did this fat end up on my body?

When people talk about wanting to lose weight, what they really mean is they want to shed fat, which means they want their body to burn off it’s fat stores. Seems simple enough. But how does that work? How does the body “burn off” fat – and where does the lost fat go?

When you eat food, you’re taking in energy (usually measured in calories). You also use a bit of energy throughout the day, even doing simple things like walking around the house or pushing a trolley down the aisle at the grocery store. Working out uses up more energy, but works in the same way. As you move, you use up the energy you’ve taken in – the same way any machine uses fuel.

There’s a reason both eating well and exercising regularly are part of a healthy lifestyle: it’s all a matter of taking in energy and using it up. If you take in less energy than you use, you’re at a deficit.

Today’s processed foods are so energy-packed that it has become really easy to take in more energy than we end up using, which means we end up with a surplus.

What happens then? First understand where the energy you take in actually goes.

What happens to the energy you take in?

The energy contained in the foods and drinks you consume either goes straight into your bloodstream for immediate use, or to replenish energy stores in your muscles or, once those stores are full, it gets stored as energy in your fat cells.

At any given moment, you’re both storing and using energy at the same time. The more of a surplus of energy you have in your system, the more energy your body will be working on storing for later in your fat cells.

Think of fat cells as something like water balloons in a bucket. The more excess energy you have, the more balloons you’ll fill up inside that bucket.

Where does fat go when you lose it?

It’s important to remember that your body will primarily use the energy stored in your blood stream and muscles before it starts using significant amounts of the energy stored as fat. Put simply, fat is the last thing your body is going to let go of when you’re using up energy stores.

Once your body starts tapping into fat stores, the more energy you use, the more fat you lose. But you don’t actually lose any of the balloons inside that bucket, they just shrink inside the bucket. Meaning that next time you take in more energy than is immediately required they’ll fill on up again.

When you use more energy than you currently have stored in your bloodstream – let’s say you’re working out in the morning and haven’t eaten breakfast yet – your body starts to pull more energy from “storage” (your bucket filled with water balloons). This is why dieting of any kind usually involves taking in less energy than you use (no matter how it’s dressed up). When enough energy leaves your cells for your body to use over a longer period of time, your fat cells start to “empty.” An energy deficit is the only way this happens.

When your fat cells empty out – when those water balloons shrink – the fat doesn’t literally burn, but those fat stores do get used as fuel, in a way. The science behind this process is sort of complicated. Eventually, the fat stored in your cells gets broken down into its components – carbon, hydrogen and oxygen. What your body does not use of those chemicals, it gets rid of. You either breathe it out (exhaling carbon dioxide) or excrete it as water (through your urine, sweat, etc.).