What happens to lost body fat when we lose weight? © Getty Images

What happens to lost body fat when we lose weight?

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Breaking down body fat doesn’t sound nearly as effective as feeling the burn.

Asked by: Terry Honeywood, Bromley


Our fat is stored as triglycerides. When we need it for energy, enzymes in the blood break it down into fatty acid chains and glycerol. The fatty acids are absorbed by cells and broken down into even smaller molecules and ‘fed’ to our mitochondria (the ‘power plants’ of our cells). The ultimate waste products of this complex sequence are just CO2 and water, which we breathe out. So when you exercise, you are turning fat into puffing and panting.

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Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.


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