Porridge is excellent mate, have it for breakfast or a while before you workout. Go to tescos or similar and buy a big bag of plain old oats,make them up and you can always add things onto it,honey,sugar,dried fruit. I would stear clear from ready break though if you cant,although its not that bad,youll A)save yourself buying bulk (2kg oats from Tescos is like £2,will last ages!) , and plain oats are better for you than the slighlty 'tampered ' with stuff.
I have it sometimes in the morning,with chocholate whey protien in it, tastes awesome and sets you up for the day with lots of Protien and good quality Carbs