Should school start later? Some think we are setting teenagers up to fail with early hours in the classroom. There is a growing campaign to start lessons later.
Lack of sleep is a health crisis says expert
You snooze, you lose? : Experts are describing teen sleep deprivation as an “epidemic". Glossary
Slugabed - A person who remains in bed due to laziness.
Melatonin - A hormone produced by your brain in response to darkness.
Crave - To want something desperately.
Adolescent - People who are still growing up, especially teenagers.
Obesity - The medical condition of being very overweight. There are many ways of measuring this, including a BMI of 30 or more. (You can work out your BMI by dividing your weight in kilograms by your height in metres squared.)
Deprived - Not having the things that are needed for a pleasant or successful life.
Curriculum - The subjects studied at school or during a course.
Inconclusive - Leading to no conclusion or definite result.