Vegetarians2 are more intelligent, according to a new study.

A study of thousands of men and women revealed that those who stick to a vegetarian¹ diet have IQs that are around five points higher than those who regularly eat meat.

Writing in the British Medical Journal, the researchers say it isn't clear why veggies are brainier - but admit the fruit and veg-rich vegetarian diet could somehow boost³ brain power.

The researchers, from the University of Southampton, tracked the fortunes of more than 8,000 volunteers for 20 years.

They found that those who were vegetarians by the age of 30 had recorded five points more on average at the age of 10.

Further analysis of the results showed those who were brainiest as children were more likely to have become vegetarian as adults.

The typical adult veggie had a childhood IQ of around 105 - around five points higher than those who continued to eat meat as they grew up.

The vegetarians were also more likely to have gained degrees and hold down high-powered jobs.

However, these differences were not reflected in their annual income, which was similar to that of non-vegetarians.

There was no difference in IQ between strict vegetarians and those who classed themselves as veggie but still ate fish or chicken.

However, vegans - vegetarians who also avoid dairy products - scored significantly lower, averaging an IQ score of 95 at the age of 10.