Prevent Obesity in Children and Adults (getting more sleep)

This should be a crime, a 2 year old at risk of heart failure-Kitty

To prevent obesity, children need adequate sleep

Want to help your kid avoid a weight problem? Limiting fast-food meals and screen time is a start, but parents may also want to set an earlier bedtime. That's the conclusion of a study published Monday in the journal Pediatrics.
http://www.boston.com/lifestyle/health/blog/dailydose/2011/01/to_prevent_obes.html

Body Weight and Sleep

Does lack of sleep make you fat, or is it the other way around? Can sleep changes play any part in weight control?
There are no straightforward answers to these questions.
Large meals make people sleepy. There are evolutionary explanations for this: when our ancestors had acquired enough food they had time to sleep, and sleep is a time when the body releases higher levels of growth hormone - kids actually grow during sleep - so the body needs nutrients. Hunger, if bad enough, prevents sleep. Our ancestors were not supposed to sleep until they put some food in their bellies.
It is also true that sleep stops - or at least reduces - feelings of hunger. That is why we can go for a much longer period of time without eating overnight (between dinner and breakfast the next morning) The hormone orexin, or hypocretin, which plays a key if not entirely understood role in regulating sleep cycles. The name orexin actually derives from the Latin word for "to eat" and hypocretin is derived from "hypo" (from hypothalmus, a part of the brain) and "cretin" (a gut hormone). This hormone was discovered separately by two research tems (hence the two names for the same hormone). Both teams were primarily interested in the physiology of eating and found the hormone when looking into appetite.
Certainly obesity can contribute to apnea and making it difficult to get a comfortable position on the bed. Pickwickian syndrome is a recognized form of sleep apnea disorder suffered by moderately to severe obesity. But even for slightly overweight people there is an interaction between sleep debt and weight.

Sleeping more can help you lose weight?

A large-scale study at Case Western Reserve University (more than 68,000 women) found that those who sleep less than 5 hours a night gain more weight over time than those who sleep 7 hours a night. The women who slept less were more likely to become obese, and here’s something that may be counterintuitive: the women who slept less consumed fewer calories than the ones who slept a full night, on average.
This new information goes against the common wisdom that overeating among the sleep-deprived explains such weight differences. Actually, there are other studies that show similar results, but a study reported in the journal Pediatrics in 2007 casts some doubt on the connection or correlation. This study looked at kids aged 10 to 19 and found that when very detailed diaries of sleep time were kept, there wasn’t as much of a relationship between weight and sleep time. This does not mean that studies linking sleep loss to excess weight are wrong, but it does point out the difficulty of measuring things as elusive as sleep time.
Why the connection between sleep time and weight?
When you are tired from not enough sleep, you might fidgeting less and burn fewer calories, but a more likely explanation is the effect of sleep deprivation on hormones.

Hormones, sleep, and weight

Adipocytes (your “fat cells”) release leptin to the bloodstream to signal sufficient fat stores; leptin therefore acts as a natural appetite supressor. The stomach releases ghrelin when it is empty signal hunger. (That’s oversimplified; ghrelin is suspected to be associated with the body’s long-term weight regulation – levels are higher in obese people than lean people.)
Sleep deprivation lowers the levels of leptin and raises levels of grehlin. It’s a double whammy hormone hit that makes you want to eat more. The brain is getting signals that the body is starving, so you crave food.
Lack of sleep affects leptin and ghrelin; short sleep time (4 hours per night or less) results lower leptin levels and higher ghrelin levels in the blood plasma. With sleep loss, low leptin and high ghrelin can give powerful dual signals that the body has an energy deficit, thus increasing food intake. (Ref)
Other hormones are intimately tied up with both sleep and weight. A reciprocal interaction of the growth hormone releasing hormone (GHRH) and corticotropin-releasing hormone play a role in sleep patterns. Ghrelin, galanin and neuropeptide Y have been shown to promote sleep.
Additionally, the orexin (hypocretin) system in the hypothalamus plays a part in the interaction between sleep and appetite. Orexin levels influence leptin release, which in turn regulates appetite and weight and tells the brain how much energy the body has. Scientists do not fully understand all these interactions. There are many competing systems and cycles in the body. A better understanding of these system might result in new avenues for addressing the sleep disorder epidemic and the obesity epidemic. Researchers recently found that oxerin appears to increase the body's sensitivity to leptin, leading to the promise that ways to boost oxerin levels may eventually become a therapy for obesity.
It is hypothesized that there are evolutionary reasons for this connection. Mother Nature may have set us up to store fat in summer in anticipation of scarcer food in the winter. Summertime has shorter nights and longer days – people tend to sleep less during the summer – so the body interprets these circadian signals as a time to increase fat deposits.
Scientists have now definitely established the link. There is a gene controlled by the circadian clock that regulates sleeping/waking and this same gene also contributes to fat deposits.
This result comes from animal tests. When researchers turned off the clock gene in mice (through genetic engineering), the mice did not gain weight on a high calorie diet compared with a control group. The glucose and lipid metabolic pathways were disrupted. The genetically modified mice did not store fat in the same quantities. A test with humans shows similar results.

Evolutionary reasons?

A potential explanation for the relationship between sleep and weight relates seasonal changes in daylight time to availability of food. Our ancestors ate more in the summer when food was plentiful. They also slept less with the short nights. During the winter, they both cut food consumption due to fewer edible resources in the environment and slept more to conserve energy.

Related stories:
Orexin blocks weight gain in mice


http://www.sleepdex.org/weight.htm