There is nothing scientific here, so apologies in advance for that, but I find oatmeal a) addictive and b) indigestible. Oatcakes in particular look so nice and healthy but if I eat one I can eat the packet. This is usually a sign (for me at least) that there's something not so good going on. Porridge without sugar is pretty palatable to me but my gut doesn't like it. Maybe it's because the oatmeal I ate had gluten traces in it. I am most resistant to infection when I stick to low carb and that means no oatmeal.