I’m sure you have all heard the saying “a moment on the lips, a life time on the hips”, usually uttered as you take a bite of your favourite piece of cake, laden with sugary fatty goodness. But what does this saying really mean, where does the fat go when you eat it? What happens to it when you lose it?

Fat is an essential part of our diet, with moderate amounts required for good health. When digested and absorbed dietary fats are generally carried around the body in the form of a triglyceride, which is a molecule made up of a glyceride backbone with three fatty acids attached.

When digested and absorbed enzymes in our blood vessels break down circulating triglycerides, allowing the fatty acids to move into muscles or heart tissues where they can be used for energy. These fatty acids also move into adipose tissue where they are stored for later use.

Now that we know where fat goes when we eat, what happens to the fat when we lose it?

The common belief is fat is converted into heat or energy when we lose it, this is however untrue. What really happens is the triglyceride molecule gets broken down into its separate atoms of carbon dioxide and hydrogen.

For the breakdown of the triglyceride molecule there needs to by oxygen present, and lots of it.

Thinking about this is a practical sense, Dr Karl Kruszelnicki’s has a great example; if you wanted to lose 10kg of fat, you would need 29kgs of oxygen to break it down, that is a whole lot of breathing. From this breakdown you would get 28kgs of carbon dioxide and 11kgs of water!!

So the real question is, what does your body do with all this excess carbon dioxide and water as a result of fat loss?

Well surprisingly the majority is lost out of your mouth, yep that ‘s right, you literally lose the fat you break down by breathing.

And the most effective way to do this is through moving. Increasing your heart rate via exercise has been proven to be the most efficient way to increase breathing and blood oxygen levels.

So there you have it, to lose fat all you need to do is breathe, eat less and move move!