The narrow boat was moored outside the Heart of England pub in Weedon when it was broken into between 2pm on Saturday February 27, and Saturday March 5.
Offenders appear to have cut through a padlock and forced a door open at the side of the boat to gain entry.
Along with food, electrical items including a TV and a radio were taken.
Anybody who has seen any suspicious activity in the area over recent weeks is asked to contact police.
Witnesses, or anyone with any information, are asked to call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555111.