A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone. Viruses must infect cells and use components of the host cell to make copies of themselves.
There isn't a specific 'most common eating disorder', but most people would have a disorder known as binge eating disorder, which is eating more than necessary. The other top 2 include anorexia nervosa or bulimia nervosa.
