A government-commissioned report has advised people who eat the highest levels of red and processed mean to limit their consumption of the foods in order to reduce the risk of bowel cancer.
Previous studies have indicated that substances in red meats such as beef, lamb and pork, and processed meats - including those that are smoked, cured, salted or chemically preserved - may increase people's risk of developing the disease.
For instance, a compound called haem - which gives red meat its colour - is broken down into harmful chemicals in the gut, and these chemicals can damage DNA in the cells lining the bowel.
In 1998, the Committee on Medical Aspects of Food and Nutrition Policy (COMA) suggested that people who eat large amounts of red and processed meat should cut back because of the possible risks.
However, red meat is an important source of iron, which is essential for health.
The Scientific Advisory Committee on Nutrition (SACN) has now reviewed the implications of reducing red and processed meat consumption and produced recommendations that aim to strike a balance between reducing the risk of bowel cancer and ensuring a sufficient intake of iron.
Its report concludes that red and processed meat is "probably" associated with an increased risk of bowel cancer.
Writing in a preface to the report, committee chair Professor Alan Jackson said: "Since the evidence does not allow quantification of the amount of red and processed meat that may be linked with increased colorectal cancer risk, SACN is advising high consumers of red and processed meat to consider reducing their intakes."
The research suggests that limiting consumption to about 70g (cooked weight) per day "would have little effect on the proportion of the population with iron intakes below the lower limit of recommended intake for iron".
This means about three rashers of bacon, three average slices of ham, or just under two large sausages per day.
At present, around 33 per cent of men and eight per cent of women are thought to consume more than 100g of red or processed meat each day.
Sara Hiom, Cancer Research UK's director of health information, said: "Eating lots of red and processed meat can increase your risk of bowel cancer and possibly stomach cancer. Red meat includes all forms of fresh, minced and frozen beef, lamb and pork. Processed meat includes sausages, bacon, ham and salami. White meat such as chicken is not likely to increase your risk of cancer. We advise people to eat smaller and fewer portions of red meat and to try using beans or pulses instead of meat in their recipes."
A large European study called EPIC, which was part-funded by Cancer Research UK, found that people who ate two 80g portions of red or processed meat each day were 30 per cent more likely to develop bowel cancer than those who ate just 20g per day.
She advised: "Keeping a healthy weight helps to reduce your risk of cancer so we recommend a balanced diet with plenty of fruit, vegetables and fibre and low in red and processed meat, salt and saturated fat."