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The Best Fish You're Not Eating

We're talking about: Atlantic mackerel
Why you should eat more of it: This high-protein, heart-healthy fish also has calcium, iron, the antioxidant coenzyme Q10, and it's low in mercury, says Alexandra Sowa, MD, a clinical instructor of medicine at Weill Cornell Medical College, in New York. Having fish like it on hand can help you reach the Food and Drug Administration's recommended 12 ounces of fish or shellfish per week.
Keep this in mind too: You can still eat tuna (which is higher in mercury than Atlantic mackerel) if you choose your go-to variety wisely—opt for skipjack tuna and canned chunk-light tuna over yellowfin and canned albacore, per the National Resource Defense Council. (As a general rule, limit intake of moderate- and high-mercury fish to 3 to 6 servings per month.)

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The Tiny Ingredients That Make Any Dish More Delicious

We're talking about: Herbs like chives, thyme, rosemary, basil and parsley
Why you should eat more of them: Herbs give meals a burst of flavor and antioxidants. If you prefer fresh over dried, store them in the refrigerator, says Maria Elena Rodriguez RD, CDN, CDE, a dietitian and manager of the Diabetes Alliance at Mount Sinai Medical Center, in New York. It'll help keep them fresh and full of nutrients longer.
Keep this in mind too: Rodriguez recommends wrapping them loosely in plastic and storing them on one of the shelves on the door—it gets slightly warmer there than other spots in the refrigerator, so there's less chance they'll freeze.

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The Things Julia Child's Told Us Not to Crowd

We're talking about: Mushrooms
Why you should eat more of them: We tend to run particularly low on vitamin D (aka the sunshine vitamin) in the winter, leaving us at higher risk of brain fog, depression and fatigue. Mushrooms are one of the few foods that are naturally rich in vitamin D, says Laura Jeffers, MEd, RD, LD, a dietitian with the Cleveland Clinic. Just like us, they create their own when they soak up UV rays—check the label to see if they've been processed in UV light or ask the vendor at your local farmers' market.
Keep this in mind too: The fungi may also help keep your immune system strong, suggests a small study in the Journal of the American College of Nutrition.
root veggies

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The Dirt-Covered Produce You Don't Buy Very Often

We're talking about: Root vegetables like parsnips and turnips
Why you should eat more of them: Because they grow underground, these veggies get direct exposure to the soil's vitamins and minerals, says Rodriguez, making them a great addition to your typical grown-above-ground vegetable lineup. One cup of parsnips has more than one-third of your daily vitamin C needs, plus potassium and folate. Turnips have a variety of B vitamins, which help your body produce energy from the foods you eat.
Keep this in mind too: Root veggies offer fiber to help regulate blood-sugar levels and boost satiety. One cup of parsnips has 6.5 grams, while one cup of turnips has 2.3 grams.

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The Classic Breakfast Food You May be Overlooking

We're talking about: Eggs
Why you should eat more of them: The "bioavailability of the nutrients" in your food probably isn't something you think about much (or at all, or even know what it means). The easy explanation: It refers to the proportion of a given nutrient that your body actually absorbs from a food and puts to use. Eggs score a perfect 100 on the bioavailability index for protein, higher than any other food.
Keep this in mind too: The yolk contains healthy fats, antioxidants and vitamins, including choline, which helps your brain and nervous system function properly, says Sowa. Women, especially those who are pregnant, may be too low on the essential nutrient, according to a review from the University of North Carolina at Chapel Hill. Worried about cholesterol? Don't be. One 2015 American Heart Journal study found that eating 3 eggs a day didn't raise cholesterol levels—even in people with coronary artery disease.

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The Salad Greens That Beat All Others

We're talking about: Mesclun
Why you should eat more of it: Plants' unique combination of health-boosting phytonutrients determine their colors, explains Jeffers, so by picking mesclun, a mixture of young, tender greens such as arugula and chicory with varied colors, you'll automatically incorporate a wider array of nutrients into each and every salad than you would if you used only lighter varieties like butter lettuce, which has less beta-carotene (a nutrient that's essential for good eye health) than darker-hued greens.
Keep this in mind too: Store them far away from the fruits in your fridge. Some fruits emit ethylene gas, which can make greens spoil prematurely.

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The Thing You Thought Only Vegetarians Ate

We're talking about: Tofu
Why you should eat more of it: "Tofu is high in protein, low in fat and is an excellent source of calcium and iron,” Jeffers says. "We should be eating it regularly.” Case in point: Okinawans, who live longer than just about any other group of people in the world, eat roughly eight times more than the average American. (Of course, the fact that they eat a lot of shiitake mushrooms, turmeric and sweet potatoes doesn't hurt, either.)
Keep this in mind too: Tofu spoils when it dries out, so store any opened and uncooked tofu in water, says Jeffers. The water will also help the tofu from absorbing other flavors floating around your fridge.

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The Colorful Veggies You've Been Keeping in the Wrong Place

We're talking about: Bell peppers
Why you should eat more of them (after you move them): They look so pretty sitting out in your fruit bowl, but in the fridge is where bell peppers actually belong. They'll better retain their nutrients, including vitamins A, C and B6. They're also high in fiber to help you feel fuller.
Keep this in mind too: Every color has a different amount of each vitamin, so make sure to eat them all (green, red, orange, yellow) for the biggest benefits, says Jeffers.

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The Other Great Source of Good-for-You Bacteria

We're talking about: Kefir
Why you should eat drink more of it: Probiotics are linked to everything from weight loss to lower blood pressure, says Sowa. You could reach for yogurt, but kefir is another good option (and something you can consume on the go). The fermented dairy drink can strengthen the immune system and potentially lower your risk of cancer, found one review in the Brazilian Journal of Microbiology.
Keep this in mind too: Kefir contains lactose, but don't worry if the natural sugar doesn't always agree with your stomach. The bacteria in kefir help your body digest it, and research suggests that over time they may help you better tolerate the lactose in other dairy products too.
cottage chese

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The Cheese You're Not Serving at Parties

We're talking about: Cottage cheese
Why you should eat more of it: A single cup of cottage cheese with 1 percent fat contains a whopping 28 grams of protein, nearly 9 grams more than a container of plain low-fat Greek yogurt. It also has 12 percent of your daily calcium needs and is a good source of phosphorous, which helps calcium strengthen your bones and prevent osteoporosis, says Jeffers.
Keep this in mind too: The fat content can vary from 0 to 4 percent, but choosing a variety with at least some fat can help you feel fuller.