Eating a stone-age diet of berries, nuts, lean meat, fish and vegetables while cutting out cereals, dairy products and refined sugar may trim the waist and protect against heart disease, a study suggests.
Volunteers were put on the Palaeolithic diet, which was what the hunter-gatherer ancestors of modern humans lived on before the development of farming.
After three weeks they had lost five pounds in weight, their waistlines were slimmer, and their blood pressure was lower.
It was also found that a clotting agent in the blood that is linked to heart disease and strokes had also dramatically reduced.
The participants - five men and nine women - only ate lean meat, unsalted fish, fresh or frozen fruit, berries, vegetables - but not beans - most kinds of nuts, canned tomatoes, lemon or lime juice, spices, and coffee or tea without milk or sugar.
Dairy products, beans, peanuts, salt, pasta, rice, sausages, sugar, fruit juices and alcohol were all banned.
As a concession the volunteers taking part in the study, at the Karolinska Institute in Sweden, were allowed up to two potatoes a day, as well as some dried fruit, cured meats and a weekly portion of fatty meat.