Obesity causes more cases of some cancers than cigarettes, Cancer Research UK has warned, as it revealed that obese people now outnumber smokers by two to one.
Just days after the charity was heavily criticised for its new obesity campaign on social media, it said more needs to be done to help people lose weight to reduce their risk of cancer.
Smoking is still the UK’s biggest preventable cause of cancer and carries a much higher risk of the disease than obesity.
But obesity is a cause of 13 different types of cancer, and trumps smoking as a leading cause for four of these types, Cancer Research UK said.
Its analysis shows that excess weight causes around 1,900 more cases of bowel cancer than smoking in the UK each year.
It also causes 1,400 more cases of kidney cancer, 460 more cases of ovarian cancer and 180 cases of liver cancer.
National data shows that around one in three adults in the UK are obese, while around a third more are overweight.
One in 10 children are obese by the age of five, rising to one in five by age 11.
The Cancer Research UK analysis used data from 2017 to show there were around 13.4 million non-smoking adults who were obese.
Meanwhile, 6.3 million adult smokers were not obese and 1.5 million adult smokers were.
Michelle Mitchell, Cancer Research UK’s chief executive, said: “As smoking rates fall and obesity rates rise, we can clearly see the impact on a national health crisis when the Government puts policies in place – and when it puts its head in the sand.
“Our children could be a smoke-free generation, but we’ve hit a devastating record high for childhood obesity, and now we need urgent Government intervention to end the epidemic.
"They still have a chance to save lives.
“Scientists have so far identified that obesity causes 13 types of cancer but the mechanisms aren’t fully understood.
“So further research is needed to find out more about the ways extra body fat can lead to cancer.”
The charity is calling on the Government to act on its ambition to halve childhood obesity rates by 2030 and introduce a 9pm watershed for junk food adverts on TV and online.
Other measures should include restricting promotional offers on unhealthy food and drinks, it said.
Professor Linda Bauld, Cancer Research UK’s prevention expert, said: “There isn’t a silver bullet to reduce obesity, but the huge fall in smoking over the years – partly thanks to advertising and environmental bans – shows that Government-led change works.
“It was needed to tackle sky-high smoking rates, and now the same is true for obesity."
Earlier this week, Cancer Research UK was criticised for its campaign drawing a parallel between smoking and obesity.
The charity’s latest billboard features a cigarette packet bearing the slogan “obesity is a cause of cancer too”.
It adds: “Like smoking, obesity puts millions of adults at greater risk of cancer.”
The advert caused a backlash on Twitter, with @KenLynch73 saying: “The message is clear that they are calling for the food and drink industry to be regulated in the same way as the tobacco industry #nannystate #slipperyslope.”
Others said weight stigma “is rife”, arguing that “blaming individuals for a situation that is complex leads to worse outcomes, not better”.
Last February, comedian and body positive campaigner Sofie Hagen criticised an advert from the charity which highlighted obesity as the leading preventable cause of cancer after smoking, calling it “incredibly damaging”.
She wrote at the time: “Society viewing fatness as a negative thing is a thing that kills more than the cancer that you MIGHT get due to MAYBE something to do with you POSSIBLY weighing MORE than a CERTAIN weight POSSIBLY MAYBE.”
Simon Stevens, chief executive of NHS England said: “Although cancer survival is at a record high, this significant progress is in danger of being undone by the fast-growing epidemic of obesity, given excess weight is linked to 13 types of cancer.
“This study is further proof that obesity is the new smoking, and the NHS can’t win the ‘battle against the bulge’ on its own; families, food businesses and government all need to play their part if we’re to avoid copying America’s damaging and costly example.”
Cancer Research's warning comes on the same day that Boris Johnson has pledged to halt hikes on so-called sin taxes, which include levies on tobacco, alcohol and sugar, should he become the next prime minister.
The frontrunner in the race to become prime minister said he would review the effectiveness of such taxes and ask whether they unfairly hit those on low incomes.
The Tory MP also vowed not to introduce new ones until the review has been completed, citing products high in sugar, fats, and salt, as examples.
In response, Ms Mitchell stressed the significance of the taxes and praised their success in lowering smoking rates and removing sugar from diets.