Recent researches are showing more and more the importance of sleep and how having a normal circadian rhythm affects our health. When we sleep, our body gets rejuvenated, growth hormones released and hopefully cortisol (stress hormones) balanced. An average adult needs about 7-8 hours of sleep every night.
When we are lacking in sleep, leptin (satiety hormone) goes down and ghrelin (hunger) hormone goes up. These are caused by an increase in cortisol which also favors fat storage around the abdominal area!! Another translation: we eat more and feel less able to stop when full.
In addition, there are also studies showing that just with a few days of sleep deprivation, there appears to be a blunt in insulin sensitivity aka insulin resistance. One of the tell tale sign of insulin resistance is feeling tired and sleepy after your meals. We should feel that we are full but no drastic change in energy level.
Most of us are so used to being dependent on coffee for energy but caffeine gives you "fake" energy. Adding stimulant (coffee) to a stressed (think high cortisol), tired body makes it "wired". What we want is a peaceful symphony of healthy hormones. Weight is just a symptom of an imbalance in our body. It is not just about calories in and calories out. Fix our hormones and our body will start working for us. So first.... we need to sleep and relax.