肥胖
如果熬夜期间经常吃“夜宵”，不但难消化，隔日还会感觉食欲不振，造成营养不均衡。因此，熬夜不仅会损害人的身体健康，还会导致内分泌絮乱，从而引发内分泌失调肥胖症。
在东南亚国家中，44.2%的大马国民有体重过重的问题，排列第一，其次为泰国（32.2%）、新加坡（30.2%）及菲律宾（26.5%）。
另外，美国《睡眠》月刊刊载的一项研究报告称，熬夜越晚的人摄入热量越多，越容易发胖。此研究涉及255名志愿者，一部分为熬夜睡眠不足，一部分为参照组。结果显示，当睡眠不足的志愿者凌晨4时上床睡觉，4个小时后即8点起床，那么他们在晚上11点后会平均摄入大约550卡路里的热量，远远超过身体所需，因而导致肥胖。
此外，若每晚睡眠时间低于6.5小时的人更容易得肥胖症。因为睡眠不足会导致人体分泌更多的“饥饿荷尔蒙”，让人过食导致肥胖。另外，人体肾上腺皮质激素和生长激素都是在夜间睡眠时才分泌的。因此经常熬夜，除了会导致内分泌紊乱，还会造成内分泌失调肥胖。
Obesity
Eating while burning the midnight oil is bad for digestion. You will lose your appetite the next day. This will result in nutritional imbalance. Therefore, staying up late will not only damage our health, it will also lead to endocrine dyscrasia, resulting in obesity.
Among ASEAN countries, around 44.2% Malaysians face the problem of overweight, followed by Thailand (32.2%), Singapore (30.2%) and the Philippines (26.5%).
A study published by the Sleep magazine from the United States reported that you consume more calories if you stay up late, consequently, you gain more weight. The study involved 255 volunteers. Some lack sleep because they stay up late. Some belong to the reference group. The results show that volunteers who go to bed at 4 a.m. and get up the next day at 8 a.m. will consume an average of about 550 calories after 11 p.m. This amount is far more than what is needed by the body, hence resulting in obesity.
Besides that, people who sleep less than 6.5 hours per night are more likely to be obese because the lack of sleep will lead to the secretion of more "ghrelin" which will make people overeat. Furthermore, the human adrenal cortex hormones and growth hormone are secreted only during sleep at night, so if you stay up late too often, it will cause endocrine disorders, which in turn leads to obesity.