Sticking to NHS guidelines on how much red or processed meat people should eat still increases the risk of bowel cancer by 20%, according to new research.
The study, part-funded by Cancer Research UK, published in the International Journal of Epidemiology, examined data from 475,581 people aged 40 to 69 at the start of the study and followed them for an average of 5.7 years.
During this time, 2,609 people developed bowel cancer.
The Department of Health recommends that consumption of things like ham, bacon and and red meat should be limited to around 70g a day, which is the average daily consumption in the UK - the equivalent of just over two rashers of bacon.
But the new research found that found that people consuming an average of 76g per day of red and processed meat had a 20% higher risk of bowel cancer compared with those who ate 21g per day.
For red meat only, the risk was 15% higher for people who ate 54g per day (about one thick slice of roast beef or one lamb chop) on average compared with those who had 8g per day.
For processed meat only, the risk was 19% higher for those who had an average of 29g per day compared with those who had an average of 5g per day.
Cancer Research UK's expert in diet and cancer, Professor Tim Key, who co-authored the study and is deputy director at the University of Oxford's cancer epidemiology unit, said: "Our results strongly suggest that people who eat red and processed meat four or more times a week have a higher risk of developing bowel cancer than those who eat red and processed meat less than twice a week.
"There's substantial evidence that red and processed meat are linked to bowel cancer, and the World Health Organisation classifies processed meat as carcinogenic and red meat as probably carcinogenic."
Around one in every 15 men and one in every 18 women will develop bowel cancer during their lifetime.
However those people having a high intake of fibre from bread and breakfast cereals lowering their risk of bowel cancer by 14%.
Dr Julie Sharp, Cancer Research UK's head of health information, said: "The Government guidelines on red and processed meat are general health advice and this study is a reminder that the more you can cut down beyond this, the more you can lower your chances of developing bowel cancer.
"This doesn't necessarily mean cutting out red and processed meat entirely, but you may want to think about simple ways to reduce how much you have and how often.
"Although breaking habits we've had for a long time can be hard, it's never too late to make healthy changes to our diet.
"You could try doing meat-free Mondays, looking for recipes using fresh chicken and fish, or swapping meat for pulses like beans and lentils in your usual meals."