In an article from Scientific American points how new analysis shows that the metabolic effects caused by even a couple nights with less than six hours of sleep may increase obesity. Here are some highlights:

No Sleep = No Good

“The researchers found that studies of people without sleep-related conditions who got consecutive nights of four to six hours of sleep revealed a wide range of negative effects involving appetite hormone signaling, physical activity, eating behavior and even fat-loss rates. ‘From a population health perspective, this helps to get people to understand that sleep deprivation really does have an impact on your health,’ Mehra says.”

Excerpt from Scientific American article

To sleep, perchance to eat less

“In one study, after just two consecutive nights of four-hours’ sleep, test subjects had a 28 percent higher ghrelin (hunger) hormone level and 18 percent lower leptin (satiety) hormone level in their blood compared with subjects who had spent 10 hours a night in bed. In the same study, for those who were sleep deprived, ‘self-reported hunger and appetite ratings significantly increased by 24 percent and 23 percent, respectively,’ noted the authors of the review paper, which was led by Julie Shlisky, a researcher at The New York Obesity Nutrition Research Center at Saint Luke’s-Roosevelt Hospital Center. “

Excerpt from Scientific American article

Stressed and sleepy

“Sleep deprivation can also lead to muscle loss and fat gain. With too little sleep, the body is also more likely to produce the stress-response hormone cortisol. After sleep deprivation, subjects in several studies had higher levels of cortisol later in the day, a time when it should be tapering off to prepare the body for rest. Heightened cortisol prompts the body to store more fat and be more inclined to use other soft tissue, such as muscle, as energy, which means that sleep-deprived dieters lose more muscle and gain more fat than do those who are well rested.”

Excerpt from Scientific American article

Parsing zzz’s

 “So is obesity causing sleep deprivation, rather than the other way around? ‘There could be a bidirectional relationship,’ Mehra says. Although sleep apnea and other conditions can make for low-quality sleep, which can then also lead to heart disease, Mehra suggests that there is ample data that show people who began as normal weight and healthy but did not get enough sleep, over time developed worse health outcomes.”

Excerpt from Scientific American article