Poor had healthier diet in the Middle Ages

"Interestingly it was the peasant class, whose diet would class today as healthy," said Dr Iona McCleery, a lecturer in medieval history at Leeds University, who heads a program which uses history to encourage children to eat better.

"The poor were semi-vegetarians who simply could not afford meat and social status. Wealth is very much associated with diet," McCleery added.

The Horrible Histories series takes dietary history to English school children to teach about the effects of a medieval diet as part of the three-year "you are what you ate" project.

"The medieval diet was very fresh food. There were very few preserves so everything was made fresh and it was low in fat and low in salt and sugar," said food historian Caroline Yeldham.