Too little sleep and overweight: a dangerous duo

You walk down the street early in the morning after spending all night to complete a project for your boss. The coffee shop is called as usual. But today siren song is more than a cup of coffee. In a way, there is an irresistible urge to buy a donut or two as well.

If ever you wondered why, read on.The number of Americans say they get sleep every night has fallen from an average of about 8.5 hours in 1960 to just under 19 hours today. 
There are probably many reasons why, but probably include 24/7 Professional extension of the "day" with artificial lighting, use of electronic devices before bedtime (blue light wavelength of these devices delays sleep onset) and widespread belief that sleep is a lower priority compared to other activities, whether work-related or pleasure.

And today, not only do most of us sleep less, but tend to weigh more, too. Over 30% of US adults are obese, compared with less than 15% of adults in the 1960s this "obesity epidemic" has been extended to children, with about 17% considered obese today. This is an alarming trend because obese children are likely to become obese adults.

Is there a relationship between sleep duration and increased the reduced obesity? Irrefutable evidence suggests there. A number of large studies involving thousands of adults have generally found that short sleepers (defined as five hours or less a night, but sometimes six hours or less) were up to 45% more likely to be obese. We do not have much data on children, but a study has shown that children who slept less than 7.5 hours per night were three times more risk of developing obesity in a period of 5 years.

Studies also show that short sleepers do not eat healthily. Above all, their diet have less variety of food, a higher percentage of calories from snacks, and a greater amount of sugar, caffeine and alcohol. They also tend to skip meals (breakfast, lunch and dinner) and also tend to snack more. These habits promote weight gain and the possible development of obesity.

Is there a scientific explanation of the feeding behavior of short sleepers? Experimental studies suggest that sleep restriction leads to abnormalities in the processing of blood sugar (glucose) and variations of hormones that control appetite. For example, ghrelin hormone stimulates the appetite, and reducing the hormone leptin. With sleep restriction, increased ghrelin levels and leptin decrease, resulting in increased hunger and appetite. In addition, these studies have shown that individuals with restricted sleep have a greater desire for high-calorie carbohydrate-rich foods.So what evidence linking lack of sleep to weight gain told us?

The bottom line is that getting enough sleep is one way to reduce the risk of weight gain and obesity. There is a tendency to put on pounds as you age. Lack of sleep will only worsen this trend. If a person is already overweight or obese, losing weight will be more difficult without adequate sleep.  

From a social perspective, the obesity epidemic, associated with increases in rates of several chronic diseases (eg, heart disease, diabetes), puts a greater burden on the health care system and contributes to rising health care costs. Adequate sleep should be included with exercise and good nutrition as one of the essential elements of good health.
By: Stuart Quan, MD,