If you're a vegetarian or vegan, you know the obvious foods to avoid — there's no confusion about where that steak came from. But the ingredients of other foods aren't so obvious.

Food labels can be confusing or even misleading, and some foods that seem meat-free can contain hidden animal products.

Take a look at our list of foods that aren't vegetarian- or vegan-friendly.

Bagels and bread products

Many bread products contain an amino acid known as L-cysteine, which is used as a softening agent. L-cysteine is derived from either human hair or poultry feathers, and it can be found in many popular brand-name products. Businesses that have acknowledged they've used L-cysteine include Lender's, Einstein Bros., McDonald's and Pizza Hut.

Beer and wine

Isinglass, a gelatin-like substance collected from the bladders of freshwater fish like the sturgeon, is used in the clarification process of many beers and wines. Other agents used for the process of fining include egg white albumen, gelatin and casein. To check if a beer or wine is vegan, visit Barnivore.com.

Candy

Numerous foods contain gelatin, a protein derived from the collagen in cow or pig bones, skin and connective tissues. It's often used as a thickening or stabilizing agent and can be found in a variety of candies, including Altoids, gummy candies and Starburst chews, among others.

Also, many red candies contain a dye made from the extracts of dried bodies of the Coccus cacti bugs. The ingredient is often listed as carmine, cochineal or carminic acid. PETA maintains a list of animal-free candy.

Caesar dressing

Most Caesar salad dressings contain anchovy paste, but there are vegetarian brands available, so be sure to read the label before you pour.

Jell-O

It's fairly common knowledge that Jell-O contains gelatin, but did you know you can make vegan Jell-O by using agar-agar, a gelatinous substance made from algae? Here's our recipe.

Marshmallows

Gelatin strikes again, but luckily you can make your own vegan marshmallows with agar-agar, so you won't miss out on any of the gooey s'mores goodness.

Non-dairy creamer

Although it has non-dairy in its name, many such creamers contain casein, a protein derived from milk.

Omega-3 products

Many products with labels that boast their heart-healthy ingredients contain omega-3 fatty acids derived from fish. For example, Tropicana's Hearth Healthy orange juice's label lists tilapia, sardine and anchovy as ingredients.

Peanuts

Some brands of peanuts, such as Planters dry roasted peanuts, also contain gelatin because the substance helps salt and other spices adhere to the nuts.

Potato chips

Some flavored potato chips, especially those flavored with powdered cheese, can contain casein, whey or animal-derived enzymes. PETA maintains a list of vegan-friendly snacks.

Refined sugar

Sugar isn't naturally white, so manufacturers process it using bone char, which is made from the bones of cattle. To avoid sugar filtered with bone char, purchase unrefined sugar or buy from brands that don't use bone-char filters.

Refried beans

Many canned refried beans are made with hydrogenated lard, so check labels to ensure you're buying vegetarian beans.

Vanilla-flavored foods

Although it's rare, some foods are flavored with Castoreum, a beaver anal secretion. As gross at that sounds, the FDA classifies it as GRAS, or "generally recognized as safe," and Castoreum is typically listed as "natural flavoring." The additive is most often used in baked goods as a vanilla substitute, but it's also been used in alcoholic beverages, puddings, ice cream, candy and chewing gum.

Worcestershire sauce

This popular sauce is made with anchovies, but vegetarian-friendly brands are available.

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