In response to another Trippist blogger's message (see below) on the difficulties of finding American (USA) food in the city, I must mention Eichholtz, the best source of anglophone expat food in all of Amsterdam.

Located at Leidsestraat 48, Eichholtz offers British and American 'delicacies' (if we can call them that?!?). The prices are premium, meaning you might end up paying 2.50 euros for a box of Kraft Macaroni and Cheese that normally 0.80 cents US (about 0.45 euro cents) at home, or for a can of Heinz Baked Beans. You can find Oreos, maple syrup (Emily!), chocolate chips, puddings, and many other preservative-filled delights. Eichholtz also stocks Dutch souvenirs, for one stop shopping!

Others can be found at this website from AmsterdamConnect, listing American food and specialty food shops around Amsterdam.