1. It will not only ruin one's mood the next day, but also lead to weight gain.

2. Firstly, they consume about 300 more calories a day, calories can quickly turn into extra weight; Secondly, when we're awake, our metabolism slows down to conserve energy, our appetite increases; Lack of sleep also leads tohormones off-kilter, therefore, our body wants more food and lacks the sensitivity to know when to stop eating.