Alice posted a question regarding sleep that I will touch on. Her question asked about a lack of sleep leading to weight gain. I'm no expert, but here goes...
An obvious point that comes to mind is that the more time you spend sleeping, the less time you are awake and consuming, whether it be alcoholic beverages, or those late-night/early morning Taco Bell trips that so many people my age are inclined to take. In college, I always snacked after dinner because I had to stay up and study!
I've read that in the later stages of sleep, our body basically goes to the shop and works on renewing cells, building muscle, regulating hormones, etc. If you aren't sleeping a proper amount and reaching that stage, then your body can't take care of itself.
Finally, if you are sleep-deprived, you won't have as much energy, and you won't be as likely to exercise. Overall, poor sleeping habits are going to affect your waking habits too!
I value my sleep a lot. Getting to bed on time and having a peaceful night are very important to me. I'm not one of those people that would sleep until noon if given the choice, and that is because I sleep well. Sleeping well to me involves the following:
1. No distractions. Silence your cell phone. Shut your door. Turn off the TV. I do not have a TV in my room and that is because I don't want to be tempted to watch it while I'm in bed. I want my mind to know that when I'm in bed, I want to sleep, not watch TV.
2. Clean sheets.
3. Lighten up on fluids one hour before bedtime so you aren't making trips to the bathroom.
4. Being comfortable. That goes for both what you wear and the bed itself. If you have an old mattress, you're just hurting yourself. Also, I absolutely cannot sleep if my feet are cold!
5. See the doctor if necessary. I grind my teeth and clench my jaw to the point that it gives me headaches and jaw pain during the day. After several visits to a TMJ specialist, I now have a few solutions to help that condition.