For all the modern advice on how to shed the kgs, the best way to lose weight is by copying our ancient ancestors, a study suggests.
The "caveman" diet popular with celebrities including Uma Thurman and Tom Jones has been given the seal of approval by scientists who found it more effective than some modern diets.
Women who adopted the so-called Palaeolithic diet lost twice as much weight within six months as those who followed a modern programme based on official health guidelines.
The diet involves eating plenty of berries, vegetables and lean meats such as chicken. Bread, rice, pasta and dairy products are banned.
The diet aims to simulate what our ancestors ate before farming began about 12,000 years ago.
A previous experiment found that men on the Palaeolithic diet for just three weeks were less likely to suffer heart attacks and strokes.
In the latest study, published in the European Journal of Clinical Nutrition, researchers divided 70 post-menopausal, overweight women into two groups. One followed a Palaeolithic diet, the other a diet based on whole-grain cereals, low-fat dairy products, fruit, pulses, fish and vegetable oils.
After six months, those on the Palaeolithic diet had lost an average of 6.2kg and 11cm from their waists, compared with 2.6kg and 5.8cm in the other group.