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Causes of cancer

Obesity, weight and cancer

Overweight and obesity is the second biggest cause of cancer

Being overweight doesn’t mean that you'll definitely develop cancer. But if you are overweight you are more likely to get cancer than if you are a healthy weight.

Find out about the causes of obesity, explore the link between obesity and cancer, and find our top tips about being healthier.

What causes obesity?

Obesity is a complex issue with many causes, but one of the biggest influences is the world we live in.

How does obesity cause cancer?

Body fat is active, telling other cells in the body what to do. The signals sent by fat cells can cause damage and cause cancer to develop.

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Some images on this page courtesy of the World Obesity Federation Image Bank: What causes obesity image; How can I lose weight and be healthier image

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