I did a label reading exercise on cereals a while ago. IIRC bran flakes were surprisingly bad and Shredded Wheat good.
Watch out for those ready made sandwiches. They're full of all sorts of stuff.
I have sugar in my tea, but I very rarely drink tea. So that's about 10 teaspoons a year.
Anyway, the reason I started this post was to add a link to an interesting youtube vid on the subject of HFCS. But it's not there anymore.
As to porridge that's a notoriously personal thing. Me, I wouldn't let salt near my porridge, the only thing I ever add salt to is eggs. I make it with 50/50 milk & water and serve it with milk. And I do it in the microwave too. But that's just what I prefer. Others differ.
As a youth I went cycling youth hostelling with a friend who insisted on a matter of principle that porridge must be cooked with salt in it, and refused to add it after serving. I thought it was vile. Hence my long standing antipathy to any kind of oat-related dogmatism.