Is loneliness really not healthy?

Hi everyone,

I just want to get a perspective on this, is loneliness really not healthy?

This is something I found on Google :

“I heard recently that living alone or feeling lonely is as harmful to health as smoking cigarettes or obesity. ... The team also cited earlier research by two of its members showing that loneliness presents the same risk to health as smoking 15 cigarettes a day or alcoholism.”

I also heard that it’s not healthy to eat alone as well… is this true?

Anyway, it’s just a question!

https://www.livescience.com/26431-loneliness-harms-health-immune-system.html

http://www.everydayhealth.com/news/loneliness-can-really-hurt-you/

How can someone not be lonely if they don’t have good social skills ? Or don’t have a lot of friends or family?