Metabolism and Sleep lose => gain weight?

Metabolism is the process your body goes through to turn calories into energy. Exercise can increase your metabolism, both while and after you work out. If you exercise enough to build more muscle, your resting metabolic rate (the speed of your metabolism when you are resting) will also be higher.That's because muscle cells use energy to create motion and fat cells just sit there. Your metabolism is the slows when you're sleeping and the fastest when you're exercising.

Not sleep = gaining weight?
You may have heard of losing weight and become unhealthy from a lack of sleep. But did you know, there's a chance of gaining weight if you don't sleep? When you sleep, levels of the hormone leptin, which signals when the body needs or does not need more food, rise. When you don't get enough sleep, or sleep is interrupted, leptin levels are low, and your body thinks it needs more calories. You'll feel hungry, and therefore eat more. So sleep more! you also burn calories from sleeping!