1/7. Obesity. The World Health Organisation has abelled it a global epidemic. One in three British adults suffers from obesity, and the incidence among children is rising. It's estimated that by the year 2020 this will be the single biggest killer on the planet. Peter Evans examines our evolutionary past and our consumer-hungry present to find out how and Why we've got SO fat. Producer Alexandra Feachem
Adam Hart-Davis on why diets don't work: page 22