So what is the right approach to this scenario?
The right approach would be to smoothly and slowly approach your child and tell him/her that the food is going to be ready in 30 minutes, or that in 30 minutes he/she must end the game so that they can go to bed or whatever reason you as a parent have.
The point is a nice gentle approach, not a harsh one. Prepare your child for finishing the game at that stage and in at the same time try to make it to a habit so that maybe next time he/she automatically prepares for quitting the game at the specific time.
Now compare this method to a method where you rip out the cable from the wall. Being able to communicate with your child, even though he/she have headphones on is a proof that you are actually handling the situation in the right way.
Also whatever you do, keep an eye on your child, even if he/she is a little bit “isolated” in his/her own room playing games. Sometimes these gamers get so badly sucked into a game that they totally forget about eating, resting and so on. In some of these cases the gamer actually get sick somehow (their body reacts in a bad way because of no food, drink or sleep for the past day or two) and people starting to blame the games for this kin of situation. We can tell you right here that that is a wrong accusation, anyone doing so is not looking at the bigger picture. As long as you have control over your playing periods, your body should not just suddenly stop working, except for situations where the gamer already is suffering from something else. Either the gamer should have control or any other adult. SOMEONE should observe, otherwise there is no excuse.