Sleep and junk food
Not getting enough sleep could kick start a craving for junk food.
In a brain scan study, participants were restricted to four hours of sleep a night for five nights, others were allowed to sleep up to nine hours.
Researchers found the reward centre of the brain was activated when people who were sleep-deprived saw pictures of unhealthy food, but not when they saw healthy food.
They also found the sleep deprived adults ate more fatty foods.
