Hi M.,
My pediatrician told us to never make a seperate dinner for your child. Always serve what you make to everyone, no exceptions. He said the child will not starve to death if he misses a meal. They will eventually eat. It will be harder on you than them, you just have to stick to your guns. You have to make them eat a little of everything you serve. It is your responsibility, you are the boss.
Sorry to say, but chicken mcnuggets and french fries are probably as unhealthy as it gets if that is your childs regular diet.
I do understand, my first child wouldn't eat anything but chunky vegetable soup when she was 2, I feel guilty to this day for feeding her a can of metal and sodium everyday for lunch and she is now 8. I followed his advice and it did work. She soon loved all her veggies and fruits.
Good luck and stay tough.