Hi, well. I've got a picky eater myself. But the thing about your boys diet is that it is all things you have bought for him and let him have at one time or another and now he has decided that it is all he will eat. Don't go through the drive through, don't buy diet pop, don't buy cocoa puffs. You'll have the items in your home that he can choose from and I'd just keep them healthier. No one has actually starved themselves holding out for cocoa puffs. Fear not that this will happen.
My boy has various issues and he is not a fan of vegis. So, I cook them up and slip them in various things like spaghetti sauce. I also make a smoothie with carrot juice and spinach (which they can't taste at all)--- it is mixed with fruit that is frozen and a touch of cinnoman and a banana.
But I just think you have to change the dynamics of the household and what is there for him to choose from. I guess everyone will have to suffer with no sugary cereal but that' okay----- everyone will live.
Just my opinion. Good luck.
His diet is unacceptable. Diet sodas contain neurotoxic sweeteners.
For individuals with diabetes there is a risk-benefit trade-off.
You have to end his drinking diet colas.
Usually when parents post complaints about their child's limited diet, it seems that the diet seems fine - there are a lot of nutritious items, it's just a very short list.
His diet seems unacceptable. I never say this, but I think you need to stop giving him access to several of these things, and you can substitute other like things. He won't starve to death - he'll eat the other things. Really, I NEVER say this kind of thing, because usually the diets are minimally okay.
How about chicken nuggets, home made sweet potato fries, healthy coco puff type cereal (the kind you get in a whole foods store) and homemade ranger cookies? I would limit him to a soda a day and then give him interesting flavored water that he can choose the flavors and mix them himself. Fun.
Holding out "over night" is probably something he'll do - and maybe hold out the next day, but he will eat eventually, and it's not like you're making him eat something disgusting to him, just healthier variations on what he is already willing to eat.
Search the net for a Ranger cookie recipe that looks good - they're packed with oatmeal and other good stuff, and you can toss in chocolate chips if you think that will entice him.
Best wishes.