I've no first hand experience but the information on the United Airlines website seems to contradict what you've been told.
If you look under 'International amenities' you'll see a reference to 'Complimentary meal service' and 'Complimentary soft drinks, juices, tea and Starbucks® coffee'. You only have to pay for your alcoholic drinks:
http://www.united.com...e/0,6867,1134,00.html
I suspect that the information you've been given refers to Continental's domestic flights (where it would be correct).
Chris



