Voluntary sleep deprivation has been shown to lead altered metabolic hormones and increased appetite. I have posted on this previously. Today, a newspaper article by Harry Jackson Jr. discusses this topic:
Sleep and insulin choreograph the dance between leptin, which tells the brain there's no need for food, and ghrelin, which tells the brain it's chow time.
Poor sleep, researchers learned, causes the dancers to start tripping over one another.
Here's what happened: The test subjects slept only four hours a night rather than eight. In only two nights, the hormones malfunctioned.
Leptin production decreased by 18 percent; ghrelin production increased by 28 percent.
On top of that, the test subjects - healthy, young, male college students - started eating like they were at a frat party. They reported craving more high-calorie, high-density, high-carbohydrate foods - including a 24 percent increase in appetite for candy, cookies, chips, nuts and starchy foods such as bread and pasta.
A week into the experiment, blood tests showed an inability to use insulin so intense that it mimicked diabetes. Also, lack of sleep increased the production of cortisol, a hormone associated with increased belly fat.
The researchers concluded that sleep starvation boosted appetite; increased appetite caused overeating; overeating caused weight gain. Weight gain causes obesity.
This short-term study suggests that voluntary sleep deprivation can contribute to obesity. Epidemiological studies have found a relationship between decreased sleep time (which can be caused by either insomnia or voluntary sleep deprivation) and weight gain.
It has been hypothesized (but not proven) that the sleep disruption produced by obstructive sleep apnea causes weight gain:
Once you're obese, you're more prone to sleep apnea, the collapse of the upper windpipe which interrupts breathing during sleep. That's the vicious circle: sleep apnea can help cause obesity, and obesity can cause sleep apnea.