Porridge has had a lot of good press and lots of people hail it as the ideal breakfast. Oats have a low glycaemic index (GI) meaning we get the energy from them more slowly, and that helps blood sugar control to be more stable. However there are a few other factors that make it a bit more complicated; the GI of a food can be changed!
The less broken down a food is (cooking is included in this) before we eat it the more slowly the absorption of energy from it is likely to be. If you use oats cut up into smaller pieces (such as the sachets for microwaving), cook it for longer, add sugar in (like honey or syrup), have a larger portion or any combination of these things, the effect on your blood sugar won’t be as steady. With these things considered oats suddenly don’t seem as useful for keeping blood sugars controlled.
There are pros and cons to think about here rather than simply being able to say porridge is best.