29. Spam

The Spam craze really peaked during the World War II era, as it was both cheap and long-lasting, but the canned pork has remained on American store shelves and household pantries for decades since.

Spam is made up of just six ingredients — pork, water, salt, potato starch, sugar and sodium nitrate — but it also contains 790 milligrams of sodium and 16 grams of fat in a single serving.

Some research suggests consuming high levels of sodium nitrate could be linked to diseases such as stomach and pancreatic cancers, heart disease and lymphoma.