Nowadays teenagers spend a lot of time playing video games, it's the most popular form of entertainment in the world; it's fun and it's a good way to spend your spare time but you shouldn't be gaming all day because it's unhealthy.
The first thing you think of when someone asks you to mention negative effects of video games is that they promote violence and they have a bad influence on young people. Children are easily influenced, and violent games can show them bad habits and make them hurt other people. They may not distinguish the real world from the virtual one. They're also addictive and this can stop the youth who spend a long time playing from getting enough exercise and not socializing.
There are a lot of different activities that could be promoted among adolescents like reading or sports, but the government and other institutions like schools should promote them providing facilities like parks where teenagers could do exercise.
In conclusion, video games aren't bad if you play them with moderation but there's no doubt that spending too much time gaming isn't good for you.