One of the low reward strategies proposed by Stephan is to 'eat gently cooked food', as in boiling and gentle steaming over roasting, grilling, frying.
I have found this to be the case. For example take some potato, mash it with some fat and it's tasty to me but take that same potato, chop it into pieces and deep fry in the same fat and voila, high reward food that I am guaranteed to over-eat.
Same goes for the delicious charred coating of a steak or rib compared to their stewed counterparts.
Now, other reward properties make sense in an evolutionary context when not co-opted by food companies, they lead us toward calorific and nutritious goodness. Why would we be more likely to favour the taste of high heat cooking?