Cancer Research UK has found that millenials are "the most overweight generation" on record.
The research predicts that 7 in 10 millenials will be overweight or obese between the ages of 35-45. This is compared with 5 in 10 of those in the 'baby boomer' generation.
"Being overweight is the UK's biggest preventable cause of cancer after smoking, but most people don't know about this substantial risk" said Alison Cod at Cancer Research UK.
Overweight or obese adults are at risk of 13 different types of cancer, including breast, bowel and kidney, the charity warned.
"The government must play a part to help people make healthy food choices. Cancer Research UK is campaigning for a ban on junk food adverts before the 9pm watershed to protect young people from advertising tactics which all too often promote fattening foods" Cox added.
Cancer Research UK is also campaigning nationwide to raise awareness about the link between cancer and obesity. They began in Aylesbury, handing out fake cigarette packets filled with chips to shoppers.
Prevention expert for Cancer Research UK, Professor Linda Bauld said: "Research shows that our evolving environment has a vital role to play in the obesity crisis. Clever marketing tactics by the food industry and greater access to unhealthy food are all likely to have contributed to the rise in obesity rates."
"Millennials are known for following seemingly healthy food trends, but nothing beats a balanced diet. Eating plenty of fruit, vegetables and other fibre filled foods like wholegrains, and cutting down on junk food is the best way to keep a healthy weight.”