Obesity, body weight and cancer

Eat at least five portions of fruit and vegetables a day Keeping a healthy body weight is one of the best ways to reduce your chances of getting cancer, after quitting smoking.

Research has shown that many types of cancer are more common in people who are overweight or obese, including:

breast cancer, in women after the menopause
bowel cancer
womb cancer
oesophageal (food pipe) cancer
pancreatic cancer
kidney cancer
gallbladder cancer

This list includes two of the most common types of cancer, and three of the hardest to treat.

The fat tissues in overweight people produce more hormones and growth factors than those in people of a healthy weight. High levels of some of these hormones, including oestrogen and insulin, can increase the risk of certain cancers.

In this section:

Find out what causes obesity, and the effects of our genes, the environment, and our behaviour
Get tips on avoiding hidden calories, controlling your portion sizes and encouraging your children to keep a healthy weight
Learn about the evidence linking body weight to cancer

Ten Top Tips

Cancer Research UK and Weight Concern have joined forces to develop Ten Top Tips for a healthy weight. These tips have been designed to fit into your daily life and are based on the best scientific evidence. Find out about the tips and ways of sticking to them in our Ten Top Tips section.

As a nation, we’re getting fatter

In Britain, people with a healthy body weight are the minority:

Two in three men (67%) and more than one in two women (56%) are either overweight or obese
One in four men (25%) and one in five women (20%) are obese

The number of overweight and obese people in the UK is increasing. A recent Government report showed that if current trends continue, the majority of people in the country will be obese by 2050, including 60% of men and 40% of women.

What is a healthy weight?

You can find out whether your weight is within the healthy range by calculating your body mass index or BMI. Check your BMI using our BMI chart.

For many people, it’s just not realistic to aim for a so-called ‘ideal weight’ for your height. Instead of focusing on a target weight, it may be more helpful to work on changing your lifestyle, which can help you reach a healthier weight.

Small changes can have big effects

Most people gain weight throughout their lives, often without realising it. Very small changes can result in large weight gains over time. For example by simply eating an excess of 50 calories per day - just half a biscuit - you could gain 5½ pounds or 2½ kg over a year. So in 5 years time you could be over 2 stone or 12½ kg heavier.

The good news is that small changes to your lifestyle can lead to a reduction in body weight. This may sound simple, but in reality it takes commitment and effort to change the habits of a lifetime. The day-to-day choices we make about our lifestyle have the greatest effect on our weight.

Losing weight and keeping it off!

The best way to lose weight is to eat healthily, eat smaller amounts and become more active. This will help you to take in less energy (calories) from food and increase the amount of energy you burn off by being more physically active.

Your first goal should be to stop putting more weight on, and then to start losing some weight. Your long-term goal will be to keep off any weight you have lost. In this section, you can read about how to avoid hidden calories and cut down on large portion sizes. Our Ten Top Tips, healthy eating and physical activity sections also have more advice that can help you reach and maintain a healthy weight. Or you could ask your GP practice or a local support group for help and information.

Your challenge is to Run 10k!

Get out into the great outdoors and get fit with Run 10k for Cancer Research UK! We’ve got 41 events in stunning and unique locations across the UK this autumn. Find out your nearest event at www.run10k.org.