You can expect wonderful seafood and quality vegetarian dishes throughout the Mekong Delta. The more popular tourist spots, such as Can Tho and Chau Doc, offer a variety of dining options, from relatively fine dining to backpacker spots offering a mix of Vietnamese and Western dishes. In other towns, options are confined to street stalls and local places, where finding an English menu can be a lottery. Local food is cheap, usually delicious, and always an adventure if you don't speak Vietnamese.
One renowned Mekong Delta specialty to seek out is Ca Tai Tuong, a grilled "elephant ear fish." Rice is a staple, and the region is famous for its noodle soups, including hu tieu (pork, prawn, and usually some offal) and bun nuoc leo (a murky pork noodle soup with thin fresh rice noodles). Banh mi (baguettes) are another cheap, easy, and tasty option.
Fruit exists in abundance, so much so that carrying fruit with you doesn't make sense. Buy it, eat it, and before you're hungry again you'll pass another fruit seller—or one will pass you; commerce is very mobile in Vietnam.