Gallstones are formed when bile becomes saturated with cholesterol – they are, in fact, composed of cholesterol crystals. They can go undetected for years but can also lead to serious conditions – infection, inflammation, colic, peritonitis and even gangrene. They are much more common in women than in men.

The WHO states that the condition affects meat eaters considerably more than it does vegetarians. A study of 800 women established that meat eaters are two-and-a-half to four times more likely to have gallstones than vegetarians (63).