Aired: Jan 26, 2009The world is affected by an obesity epidemic, but why is it that not everyone...
Horizon
Season 46 Episode 5: Why Do We Talk?
Why are you more likely to have a heart attack at eight o'clock in the morning or crash your car on the motorway at two o'clock in the afternoon? Can taking your medication at the right time of day really save your life? And have you ever wondered why teenagers will not get out of bed in the morning? The answers to these questions lie in the secret world of the biological clock.
