All about the balance. 中道。
The ancients who understood the Tao, followed the principle of Yin and Yang, and lived in harmony with the technology and numerology (or fated things).
They ate and drank in moderation, worked and rested regularly, and will never overstrain themselves caused by the delusion (in their thought). So they can have the unity of their physical form and spirit, and lived to an old age of more than a hundred.
But nowadays people don't behave like this. They drink wine like water, lead a delusive life and think it is normal. Their passions dissipate their vital energy. They continue to maniplate their spirit to satisfy their heart (desire) that is against the joy of life.
Nothing is in moderation in their life.
So they aged, and their sign of aging can be seen from an age of fifty.
- Huang Di Nei Jing (The Yellow Emperor's Inner Canon)