Parents have been advised to replace ham with chicken, fish or cheese

The World Cancer Research Fund said parents should not put ham and other processed meat into their children’s lunchbox to avoid them developing a cancer risk in later life. They said that parents should act now to stop their children developing a taste for smoked, salted or cured meats as eating too much over decades can raise the risk of bowel cancer.

However the UK’s Food Standards Agency said ham and processed meats were fine for lunchboxes but should not be eaten “too often”.

Some estimates suggest that thousands of cases of bowel cancer could be prevented if everyone limited their intake of processed meat to 70g a week – equivalent to three rashers of bacon.

The research by the World Cancer Research Fund shows that curing, salting or adding preservatives to meat can introduce carcinogenic substances. It says meats like ham and salami should be replaced with chicken, fish or cheese.

Marni Craze, the charity’s Children’s education manager says ‘It is better if children learn to view processed meat as an occasional treat if it is eaten at all. Putting ham or high calorie snacks in your child\s lunchbox may seem like a convenient option, particularly for parents who do not have a lot of time to prepare their child’s lunchbox. But packed lunches are a part of a child’s diet that is relatively easy to control and it does not have to take too much time or effort to prepare a healthy lunch.’

However, Sian Porter, a dietitian and spokesperson for the British Dietetic Association says ‘If you add something healthy to a ham sandwich, such as tomato or salad, then that helps too. My advice would be to buy the best quality ham you can, and eat less of it, or eat it less frequently.’