The Fitness Zone
Scientists have pinpointed the causal connection between lack of sleep and increased obesity in industrialised nations.
Researchers in the psychology department at the University of California used MRI scans to firstly image the brains of 23 participants who had had a full night's sleep, and then image them a second time after a sleep-deprived night. The recommended average amount of sleep is 7 to 9 hours a night. However, this can differ according to their lifestyle, age, diet and environment.
When asked to select food items and portion sizes from 80 pictures, scientists noticed the brain area that evaluates appetite was impaired, while the brain area associated with cravings was stimulated.
High calorie foods became more desirable to the sleep deprived participants," explained Matthew Walker, who was a co-author of the study.
They concluded that ensuring regular sufficient sleep might be an important factor in weight control. The study was published in the journal Nature Communications.
World Health Organisation figures show 1.4 billion adults worldwide , which is more than one-third of the world's adult population, were overweight in 2008. That is double the number in 1980. Globally, obesity takes the lives of 2.8 million adults every year.
Few Australian adults get the recommended 7 to 9 hours of sleep per night. A sufficient amount of sleep is key to good mental and physical health and, as Walker's study showed, can reduce cravings for high calorie food. Adequate sleep is an important factor for overall good health, along with diet and exercise.