They also should be on the ground where you left them before loading your checkpoint save. Scroll down and you should find that the cans are back in your inventory. As the recover process follows, quickly load your last checkpoint and access your inventory. Once you retrieve around 10 or 20 cans, toss it on the ground and then kill yourself. In an early chapter, you'll meet a girl who asks you to scrounge along the beach for water and food.
Canned Food Exploit (Dead Island Riptide)