With only 24hrs in the day, many of us find it difficult to fit in everything we want to get done in the day. Unfortunatley instead of cutting back on activities or time in front of the T.V, reasearch suggests that many of us are cutting back on sleep. In the last 40 years we have cut back on our sleep by an average of about 1-2 hours per night.
It is recommended that adults recieve about 7-9hrs of a good nights sleep per night to help with restoring our minds and bodies. This includes helping to restore our immune system, decreasing irritability and impatience, and lowering blood pressure. Now there is also more and more evidence to suggest that lack of sleep can affect our metabolism and result in increased weight and difficulty to lose weight.
Recently I watched a presentation from theCanadian Obesity Summit which discusses how sleep (or lack thereof) can be part of the contribution to obesity and could be the cause of some peoples futile attempts to lose weight.
Jean Phillip Chaput points out that obesity rates in the U.S have increased by 19.4% in the past 40 years where the sleep rates in U.S have decreased by 1-2 hours in the same amount of time. He also points out that sleep depreviation is the major risk factor for overweight and obesity in both children and adults. And examines a study that showed that adults who slept less than 5 hours per night were 55% more likly to be more obese than those who slept more; and that children who slept less than 10hrs per night were 89% more likely to be obese than those who slept longer.
So what are some of the possible reasons for this relationship between decreased sleep duration and obesity? Well for one thing, the longer we stay awake the more hours in the day there are for us to overeat. Most of us who aren’t getting 7-8 hours of sleep per day may likely be spending some of our sleeping time infront of the tv with chips and popcorn on hand. Not only are there more hours to spend eating but one study showed that sleep restricted people had increased neuronal activity in response to food stimuli than those who slept 9 hrs per night; showing that reduced sleep may make people overeat. In addition, restricted sleep also increases appetite for more calorie dense foods especially carbohydrate rich foods.
To add to this, studies have also found that decreased sleep affects physical activity. This can likely be that people who do not get enough sleep don’t have enough energy to partake in physical activity. Another side to this could be that physical activity helps with sleep and that people who are physically active (at least 30min per day) will have better quality sleep as a result.
Not only can decreased sleep result in weight gain but it can also impact your attempts to lose weight. A study found that men on a calorie restricted diet who were sleep restricted lost 55% fat mass and 60% muscle mass compared to their counterparts who slept 8.5hrs per night. So if you’re trying to lose weight while depriving yourself of sleep, you may be losing muscle mass instead of what you’re trying to lose (fat mass).
While this research doesn’t necessarily prove that sleep restriction is the cause of obesity, it definitely suggests that sleep could be a major risk factor. The next time you’re battling to lose those last 10 pounds and think you just can’t exersice any more or eat any less than you are maybe you should take a look at your sleep hygeine. Are you getting enough quality sleep?
I think it’s time for us to start decreasing our screan time and our dependence on caffeine to keep alert during the day and pay more attention to getting enough sleep during the night.