How Do I Upgrade My Power Supply Do I Need To Buy A New Power Supply To Run A More Pwerfull Graphics Card?

Do i need to buy a new power supply to run a more pwerfull graphics card? - how do i upgrade my power supply

A man at work told me that I must improve my diet if I fit more powerful graphics card and when I upgrade memory.h told me that I have is about 400W, true.Also As I know how to adapt is. I need it to, if the network, such as long hours, so they have time for their business.