There can be many reasons for sleep disruption including stress, high caffeine intake, poor blood sugar regulation during the day, alcohol or eating late at night. Indeed, with our busy lifestyles, sometimes we simply don't allocate enough time for sleep.  

When asleep, our body is hard at work. Many activities are taking place such as immune activity, tissue repair and hormonal changes which control many different functions in the body. Amongst these hormones is leptin, a hormone that suppresses appetite, and ghrelin an appetite stimulant hormone.  Research shows sleep restriction is associated with reductions in leptin and elevations in ghrelin. This change leads to increased hunger especially for high calorie, carbohydrate-rich foods.   So to put it simply, someone is more likely to make poor food choices if they’ve had insufficient sleep.

Indeed, studies have shown that sleep loss is associated with an increase in appetite and reveal a negative association between self-reported sleep duration and body mass index.  This is important news for those who are trying to manage their weight and feel that they are not achieving sufficient sleep.

To support this, other studies have shown a relationship between fewer sleeping hours and body mass index. Those people who reported to have less sleep were, on average, carrying more weight than those who reported getting a good night's sleep.  This is important information for anyone trying to manage their weight.  It's not only about calories in / calories out – addressing lifestyle factors may play a part in helping to achieve weight loss goals.

It's interesting to note that over the latter half of the 20th century sleep duration appears to have decreased by 1.5-2 hours per night, with many people regularly sleeping for only 5-6 hours.  This trend seems to mirror the rise in obesity levels.  Could lack of sleep be a contributing factor in the current obesity epidemic?

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