Tag Archives: overweight

Obesity and cancer risk: Guardian health editor and author Sarah Boseley on the serious impacts of being overweight

Sarah Boseley

Sarah Boseley is the Guardian’s award-winning health editor and author  of ‘The Shape We’re In: How junk food and diets are shortening our lives’. Here she writes about the dangers of obesity, and calls for more robust action to warn people of the impact of being overweight:

‘The tombstone adverts on mainstream national television of the mid-80s warning us of that Aids was a death sentence were unforgettable. The more recent anti-smoking adverts showing cigarettes metamorphosing into tumours were stomach-turning. Governments in the UK have successfully mounted powerful public health campaigns – and yet, when it comes to the serious and growing health impact of obesity, the warning voices are barely more than whispers. It appears the best we can manage are the blob-like cartoon figures of Change4Life who try to jolly us along into attempting a bit more exercise and watching our diet. The humour and gentle tone of it all is a disincentive to taking it seriously.

Small wonder then that obesity is growing and most people appear not to understand that it has the potential to shorten our lives and wreck their quality with disability. The warnings of the public health community are drowned by the multi-million pound marketing of the food and drink industry which has, in the last three decades, succeeded in persuading us to eat more and to cut corners by buying packaged food and ready meals and snacks in the name of convenience and living life to the full. We have bought their message that cooking is too time-consuming for the working man and woman, except perhaps at weekends. We have believed that we deserve frequent treats and sweets and sugar-sweetened fizzy drinks and that the old message of not eating between meals is out-dated. And we sit still more and move less. So now we are in a situation we would never have imagined in the 1980s, where most of us – indeed, nearly two-thirds of us – are overweight or obese.

We no longer notice that people are fat. Although the f-word and the o-word still carry a massive stigma and are thought insulting (with the result that a lot of GPs are reluctant to raise the weight issue with their patients) we don’t see what is happening around us because overweight has become normal. It’s particularly true in some populations, where people have less money and less options in life and filling, fattening food has become ever cheaper. In communities where fried chicken and fried fish takeaways proliferate, waist measurements are dangerously large.

The toll this is taking of our health is grim. Most cases of type 2 diabetes are directly linked to overweight and the numbers of new diagnoses are soaring. The disease already swallows 10% of the NHS budget and that is growing. Type 2 diabetes can be controlled by drugs, but in too many cases there are complications, including blindness and amputations. Heart disease and strokes are fairly well-known consequences of obesity and efforts to limit the damage include the controversial handing out of statins to ever larger numbers of people. But few people who are overweight understand how much it increases their risk of cancer.


According to the World Health Organisation, overweight and obesity are the most significant preventable causes of cancer after smoking – yet most people are more likely to fret about air pollution or food colourants. The unwillingness on the part of doctors, politicians (concerned about damaging the profitable UK food industry) and most of us in social situations to be open about the dangers of getting fat have distorted the picture. But obesity is responsible for an estimated 17,000 cancers in the UK every year.

The evidence is strong in breast cancers in women after the menopause. Between 7% and 15% of those breast cancers are caused by obesity, scientists believe. The Million Women study in the UK, run from Oxford University, found that post-menopausal women who were obese had a 30% higher risk of breast cancer than those of normal weight. And because weight is so hard to shift, women who put it on in their youth have an increased risk of breast cancer in the long term.

Obesity is one of the most important causes of bowel cancer, which few realise, causing more than one in ten cases. It raises the risk of endometrial or womb cancer three to four times and triples the risk of oesophageal cancer. It is implicated in pancreatic, kidney and gallbladder cancer and there is some evidence that it could also be a factor in others, from brain cancer to leukaemia and ovarian cancer before the menopause.

This is preventable risk, but too many people have no idea of the danger they could be in. Our “have it all” culture encourages us to eat and drink what we like, when we like and racks up the profits of the food and drink companies who compete with each other for ever bigger, more profitable shares of the market. Traffic light food labelling is an achievement, but gets nowhere near the sort of health warning we need. Cigarette packets tell us stridently that smoking could cause us to get cancer. Isn’t it about time that we heard a similar message concerning over-eating and junk food and drink?’


This blog was commissioned by WCRF UK. The views of the author do not necessarily reflect those of WCRF UK, or any of its partners.

Accurate weight perception: an important determinant of healthy weight

Weight perception
Are we failing to see the truth?

Following today’s report, which proposes Governments get tough on obesity, we look at recent research, which suggests that a skewed perception of body weight may also be a barrier to effective weight loss.

Obesity-related illness

Recently published figures on obesity, physical activity and diet show that around a quarter of adults in England were obese in 2009 [1]. Today’s report suggests this figure is set to rise in the UK to 40% by 2030.

The evidence linking body fat to several cancers is now so convincing that experts believe that maintaining a healthy body weight is the most important way, after not smoking, that people can protect themselves against cancer [2]. They recommend that if people are already overweight, they should aim to lose weight to move towards the healthy range (BMI of 18.5-24.9).

Misperception: a barrier to weight loss

Recent research from the United States suggests that a skewed perception of body weight may be a barrier to effective weight loss and a possible area for intervention [3]. Interviewing 2,056 obese adults from the Dallas Heart Study, researchers found that eight per cent of participants had ‘body size misperception’ – that is, they failed to recognise their actual body size and their need to lose weight.

Those individuals also felt more satisfied with their overall health than the other participants and were less likely to exercise. They visited health professionals less often and were more likely to believe that they had a low lifetime risk of obesity-related illness. Two-thirds of those with body size misperception also estimated that they were at low lifetime risk of becoming obese, despite already being obese.

Misperception: more common in overweight subjects

Another study in Texas looked at perceived weight versus actual weight in 2,224 women aged between 18 and 25. It found that weight misperception was more common in overweight women than in their healthy weight counterparts (23 per cent compared to 16 per cent) [4].

This overestimation of health and underestimation of risk could have significant health implications. Individuals who believe they do not have any excess weight to lose may be less likely to undertake weight loss behaviours, and therefore less likely to improve their health and lower their risk of cancer and other diseases.

Parents misjudge children’s weight too

In a recent BBC interview, consultant paediatrician Professor Mary Rudolf suggested that children’s weight is also often misjudged. Many parents are surprised, and some are upset, to learn that their child is overweight, or even obese [5].

The interview cites a National Opinion Poll involving over 1,000 parents of children aged four to seven, which showed that only 14 per cent of those with an obese child thought that their child was overweight.

Professor Rudolf suggests that this is partly due to more children being overweight, making it seem more normal. Stories in the media have also tended to focus on children who are very obese, making even overweight children look slim in comparison.

Why children’s weight matters

Evidence shows that children who are overweight are likely to remain overweight as adults, or to become obese. It is important that parents and health professionals recognise when a child is overweight or obese so that they can provide the necessary support to help that child to choose healthier foods, be more physically active and manage their weight as they grow.

For ideas on how to eat well and be physically active as a family, as well as games, recipes and make-and-do activities for children, visit the Great Grub Club.


1. The NHS Information Centre. Statistics on Obesity, Physical Activity and Diet: England, 2011. 
2. WCRF/AICR. Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Washington DC: AICR; 2007. 
3. Powell MT et al. Body size misperception: a novel determinant in the obesity epidemic. Arch Intern Med. 2010;170(18):1695-7. 
4. Rahman M et al. Self-perception of weight and its association with weight-related behaviours in young, reproductive-aged women. Obstet Gynecol. 2010;116:1274-80. 
5. BBC News: Health. Parents ‘do not recognise obesity in their children’ [online]. 2011. Available at: www.bbc.co.uk/news/ health-12226744

Safeguarding children from fast food marketing

Two boys play football in park
Physical activity important to fight obesity

These days most parents are acutely aware that their children are seen as a valuable market by a wide range of manufacturers. But many may be unaware of the level of sophistication used by the marketing departments of large food and drink companies to sell their products, which are often high in fat, sugar or salt.

Last month, World Cancer Research Fund (WCRF) Health Promotion Officer Rachel Clark attended a conference organised by the International Association for the Study of Obesity (IASO), which looked at the marketing of unhealthy foods to children, and returned with some shocking reports, some of which were highlighted in yesterday’s Daily Mail.

Among the tactics used by firms to target children are: the use of online games (known as ‘advergames’), often on websites owned by the advertiser; utilising social media sites such as Facebook: employing cartoon characters (like Tony the Tiger) and other images designed to appeal to kids on packaging; mobile phone marketing; and event sponsorship, particularly of high-profile sporting occasions (think Coca-Cola and McDonald’s involvement with the Olympics).

Children are also recruited by companies to act as ‘brand representatives’ to promote products to their friends.

Jane Landon, the Deputy Chief Executive of the National Heart Forum, told the conference that much of this marketing took place online where self-regulatory rules do not hold much sway.

Many of these methods bypass parental control completely and appeal to youngsters who are not old enough to understand that they are being sold something, particularly when it’s in the form of a game or some other fun activity. Sheffield University’s Dr Mark Blades described how children can distinguish TV advertising from programmes by the age of five but even at the age of 12 will have difficulty drawing the same distinction on a web page.

The conference also heard how the multi-million pound junk food marketing machine is easily surpassing the efforts of charities, the government and other bodies promoting healthy eating.

Prof Charlie Lewis, of the University of Lancaster, said NHS campaigns like 5 A Day and Change for Life were having little impact on childhood obesity while brand games and entertainment are having a powerful influence on children’s choices.

And IASO Director of Policy Dr Tim Lobstein criticised self-regulation among food and drink manufacturers, calling the system “ambiguous” and its results “questionable”. He told the Mail: “Companies can now use new technologies to encourage children to market to each other and bypass any parental controls.”

The findings of the IASO compliment the 12 recommendations of last year’s World Health Assembly regarding the marketing of food and drink to children.

This listed the following ways in which children are targeted by companies: advertising; sponsorship; product placement; sales promotion; cross promotion using celebrities; brand mascots or characters popular with children; websites; packaging and labelling; point of purchase displays; emails and text messages; viral marketing; and, finally, good old word-of-mouth.

WCRF is concerned about the UK’s increasingly overweight population as being overweight is a major factor in developing cancer. This is why we encourage healthy eating and physical activity in children as a healthy childhood is likely to transfer into a healthy adulthood.

Quarter of adults in UK are obese

Obesity: a cancer risk factor
Obesity: a cancer risk factor

A new report that includes obesity statistics for the European Union makes depressing reading.

It has found that 25% of adults in the UK are obese, which is the highest proportion in Europe.

The European Union average is 15%, with other poorly performing countries including Ireland, Malta, Iceland and Luxembourg.

There are, of course, lots of reasons why high obesity levels are bad news. But from our perspective, higher levels of obesity mean higher rates of cancer.

This is because, after not smoking, maintaining a healthy weight is the most important thing you can do for cancer prevention. In fact, there are six types of cancer where there is convincing evidence that excess body fat increases risk, including breast and bowel cancer, two of the most common cancers in the UK.

And scientists estimate about 19,000 cases of cancer are diagnosed in the UK every year that could have been prevented through maintaining a healthy weight.

Not enough people know about the link between obesity and cancer risk. But while raising awareness about the importance of a healthy weight for cancer prevention will make a difference, it is only ever going to be part of the solution.

Our Policy Report set out the changes in society that need to happen to make it easier for people to make the sort of changes that can help prevent cancer, such as more walking and cycling facilities.

And helping to tackle obesity is a big part of this.

Our revamped BMI calculator

Being overweight increases cancer risk
Being overweight increases cancer risk

World Cancer Research Fund (WCRF UK) has had an online body mass index (BMI) calculator for some time.

But today we have launched a revamped version of the BMI calculator that is easier to use.

Previously, people had to enter their weight in pounds to calculate their BMI. But we have changed this to be in stones and pounds.

Once people have calculated their BMI, we have also made it easier for them to find more relevant information, including ideas for healthy recipes.

But why, you might be asking, is BMI relevant to cancer?

The reason is that there is convincing scientific evidence that excess body fat increases risk of six types of cancer, including breast cancer and bowel cancer. This is why for cancer prevention we recommend being as lean as possible without becoming underweight.

In fact, scientists now say that, after not smoking, maintaining a healthy weight is the most important thing you can do for cancer prevention.

This is why it is good for people to know whether or not they are a healthy weight. Measuring your BMI is one way of finding out.

It is important to emphasise that BMI is only a guide to whether you are a healthy weight. It may not be relevant for some groups of people such as bodybuilders or pregnant women.

But it is a useful guide for most people.

And if people are aware they are overweight or obese, it may encourage them to make the kind of simple changes that can help them get back into the healthy weight category.

So why not try our new BMI calculator and let us know if you have any comments about whether it’s easy to use or suggestions about how we can improve it further.