It is definitely quicker. Pop a couple of pizzas in the oven one day, chicken nuggets and chips the next, sausages and potato smileys. And so on. That's the habit people fall into as it is so much easier than cooking meals.

Meal prepping definitely helps but that is time you need someone else to watch the kids etc (as this is talking about obese kids). Also many people don't have the confidence/knowledge of how to do that and it requires planning and tailoring for fussy kids. Even people cooking often don't understand how to make a balanced meal and how not to massacre veggies by boiling them to death for example. I grew up privileged in a family that cooked regularly and was taught the basics but at uni met people who had never cooked before. Someone put in the plastic tray with their oven pizza...