In my opinion (with no science to support me) it is easy to 'give yourself anorexia' by starving yourself and making use of thinspo materials.
Although there have been campaigns to remove the worst thinspo material from popular sites it's still easily available.
As other people say, the re-feeding is also tricky and dangerous. So, while going hungry is probably okay for most people please be careful and get help early if you think it's becoming a problem.
When adjusted for other factors anorexia has the highest mortality rate of the mental illnesses, killing something like 20% of sufferers. (Although that number is a bit old now.)