Insufficient Sleep and Efforts to Reduce Adiposity

Okay, I'm still reading the first paragraph of the "Burn Fat While You Sleep" study, and already I've learned two new words:

1. catabolic - related to catabolism, the process of breaking down complex molecules into simpler ones, releasing energy. Polysaccarides (starches), lipids (fats) and proteins are broken down into monosaccarides (simple sugars), fatty acids, and amino acids. 
2. orexigenic - increasing or stimulating the apetite; the opposite is anorexigenic. Ghrelin, an orexigenic hormone produced in the lining of your stomach, makes you feel hungry. Leptin, an anorexigenic hormone produced in your fat cells, makes you feel satiated. 

After reading the whole thing, I think it makes sense, but I hope there's additional research, especially since this study only involved ten people. The study found that people who got more sleep burned more fat while they slept than people who got less sleep. It's important to keep in mind that both groups lost the same amount of weight, but for the group that got less sleep, more of that lost weight was in the form of lean tissue (such as muscle). Another thing to keep in mind is that it only works on people who are on calorie-restricted diets (in this case, defined as 20 kcals per kg of body weight). If you're overeating, you can't lose weight by sleeping more. If that worked, there would be a lot fewer fat people around. 

This is definitely something to think about when trying to squeeze more exercise into your day, at the expense of sleep. And it has also made me more interested in finding out about these hormones, ghrelin and leptin, that can make you feel either hungry or full. 

I read a bit about leptin a while back, and I've been thinking about it ever since. The view that fat people are fat because they don't have enough willpower or self-control or whatever overlooks the fact that these hormones can have very strong effects on our behavior.