Hormones, Obesity and Sleep

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Childhood Obesity News has discussed the importance of the quality and quantity of sleep, especially for young children and teenagers. One study showed that young teenage boys are much more adversely affected by sleep deprivation than are girls in the same age group. A recent Australian study showed that the timing of sleep is more important than the duration. To stay at low risk for obesity, kids need to go to sleep early and get up early.

Computer activities and television deserve a large part of the blame for kids staying up late. This is certainly the opinion of the American Academy of Pediatrics, which recommends asking two questions: is there a television or computer in the child’s bedroom, and how many  hours per day are being spent on it? Critics say such things as:

Computer games are infectious and addictive for adults and children alike. More and more kids, as young as 5, are playing these games long after their bedtime, resulting in a lack of sleep…. Children’s being tired and crabby first thing in the morning lends visual evidence to them not getting enough sleep. However, it’s what is happening unseen to their metabolism that has the means to create unhealthy kids.

The same source urges parents to set a strict bedtime, and offers a set of parameters:

Toddlers, age 1 to 3 need to sleep 10 to 13 hours.
4 and 5 year olds need 10 to 12 hours.
6 to 9 year olds need about 10 hours.
10 to 12 year olds need 9 to 9 ½ hours.
Teenagers and adolescents need 8 to 9 ½ hours.

But what exactly is going on inside these young organisms? Not all the details are known. But sleep deprivation appears to stimulate the secretion of ghrelin (which is known as the appetite hormone) while reducing the production of leptin (which tells us when we’ve had enough). So sleep-deprived kids feel hungry, don’t feel full for long, and tend to put on weight. Some researchers are exploring these pathways with great hope. As David Berreby puts it, ” ‘things that alter the body’s fat metabolism’ is a much wider category than food.”

Another good explainer is Sean Croxton:

Hormones store fat. Hormones should be in balance. You don’t want too much of them, you don’t want too little of them, you want them to be right there in the middle, nice and balanced and when they’re not, you’re going to have some issues. Your hormones would tell your cells what to do. If your cells are getting the wrong messages, then your body is not going to function very well.

Last year, a study came from the Boulder campus of the University of Colorado. The number of subjects was small — eight women and eight men — with an average age of 22. They spent two weeks in a sleep lab, including a five-night spell of only five hours of sleep per night. As a result, they definitely gained weight. Karen Rowan wrote:

The researchers found that participants burned about 5 percent more calories when their sleep was limited to five hours, however, they consumed about 6 percent more calories, compared with when they were allowed nine hours… Although the participants ate less at breakfast when they had five hours of sleep, they ate more over the rest of the day, and especially consumed more calories late in the evening.

This team seems to suspect that something else is going on besides changes in the levels of ghrelin and leptin, so that might be a development worth keeping an eye on. The report was careful to say that getting enough sleep, in and of itself, is no guarantee that a person will lose weight. Getting enough sleep just sets the stage. It’s a necessary, but not a sufficient, condition. Soon afterward, Uppsala University announced some upsetting news, as conveyed by Jennifer Welsh:

When you lose out on even just one night of sleep you end up binging on food, especially high calorie food…. Not only does a loss of sleep decrease your self-control and decision-making abilities, but it also seems to make you hungrier…. The subjects ended up buying more calories, and more food, than they did if they weren’t sleep deprived. Even though the men had eaten, they had higher levels of ghrelin in their blood…

So there are still more twists and turns to explore.

Your responses and feedback are welcome!

Source: “Hidden Drivers of Childhood Obesity Operate Behind the Scenes,” ScientificAmerican.com, 10/31/11
Source: “Lack Of Sleep Makes Your Kids Hungry,” ArticlesBase.com, 03/01/10
Source: “David Berreby rejects the diet+exercise model of obesity epidemic causation.,” AeonMagazine.com, 06/19/13
Source: “The Dark Side of Fat Loss with Sean Croxton,” BulletproofExec.com
Source: “Inadequate sleep may make you eat more,” FoxNews.com, 03/12/13
Source: “Why Losing Sleep Can Make You Want To Buy A Really Fattening Doughnut,” Yahoo.com, 09/09/13
Image by Paul

 

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