Brits eat a whopping 100 million fast food and takeaway meals every week, it has been revealed.
Despite being better informed about diet, young adults are seven times more likely to tuck into unhealthy meals at least once a week, Cancer Research UK found.
Men are more keen on ready meals, sweets and soft drinks, with just over 55% tucking into convenience foods at least once per week compared to 44% of women.
Overall, UK adults consume up to 300 calories more than the recommended daily amount.
Alison Cox, director of cancer prevention at Cancer Research UK, said: "These figures show that 'grab and go' foods and a growing appetite for takeaways and ready meals are helping to propel us towards an epidemic of larger waistlines and increased cancer risk."
The figures, based on a YouGov survey, follow an earlier report showing that just one in four people are aware of the link between obesity and cancer, with 63% of adults recorded as obese in 2015.
The findings also showed 71% of men and 61% of women were "sufficiently active", including 46% of obese participants.
This led the report to conclude exercise is not the only solution to reducing the obesity epidemic.
Jyotsna Vohra, head of the Policy Research Centre for Cancer Prevention, the team which published the report, said the onus should be on food manufacturers to reduce salt, sugar and fat levels in their products, in addition to informing the public about healthier options.
She said: "We do know that obesity has been increasing in the UK due to lifestyle choices that people make, including turning to ready meals because of convenience.
"There is no one silver bullet related to obesity.
"We do think the (food) industry needs to make healthy food more accessible to the public.
"We want the food industry to look at the report and look at how they can make (their products) healthier."