Hey, Leatherface, drop that donut. The stuff you eat can help or hurt your looks.

“It’s a cliché to say ‘you are what you eat,’ but for better or worse your skin and hair can reveal your diet choices,” says Marisa Moore, a registered dietitian nutritionist and former spokesperson for the American Academy of Dietetics.

While some lucky dudes are genetically blessed with healthy looking hair and skin regardless of what they eat, most of us need certain vitamins and nutrients in our diets to look our best, Moore says.

Here, she and other diet experts explain the best foods to eat for your skin and hair.

Vitamin C absorbs the damaging antioxidants that flood your skin after sun exposure, shows research from UC Berkeley. That doesn’t mean C will protect you from skin cancer. It just helps prevent the premature aging that can result from too much sun time. Red bell pepper has 30 percent more vitamin C per serving than an orange, according to the USDA.

Much like vitamin C, a substance called lutein—found in avocado—protects your skin from UV damage, Moore says.

This nut is packed with biotin, a kind of B vitamin your body needs to make the keratin structure that underlies healthy hair and the outer layers of your skin, says Joy Dubost, Ph.D., R.D., a food scientist and spokesperson for the American Academy of Dietetics. Eggs are also a good biotin source, she says.

Collagen is the substance that holds your skin cells together and gives it its elasticity. It also strengthens hair, Dubost says. To form collagen, your body needs a mineral called silica. “The best food source of silica is beer,” Dubost says.

Most orange fruits and vegetables—from carrots to sweet potatoes—contain beta-carotene. So does spinach and dark leafy greens. Your body converts beta-carotene into “active vitamin A,” also called retinol, which is important for healthy looking skin, Moore says. (Retinol is also important for your eyesight.)

Omega-3 helps “maintain cell membranes” in your skin, hair, and throughout your body, Moore says. So not only does it keep your skin looking healthy, but it’s also been linked to lower rates of arthritis and other diseases. Salmon is packed with the stuff. So are other fatty fish and olive oil.

Along with fortified breakfast cereals, lentils and beans, red meat is a good source of iron, Dubost says. Iron deficiencies are common, and can lead to hair loss, she says. Too little iron can also make you feel wiped out during the day.

While sugary milk chocolate can hurt your complexion, low-sugar dark chocolate can help it. The antioxidants in dark chocolate help your skin look and feel smooth and supple, suggests a study in the Journal of Nutrition.

Eat more of the stuff on this list, and you’ll give your skin and hair the nutrients it needs to look and feel healthy.