10 Healthy Foods You Can't Eat on the Keto Diet

You might be surprised by how many nutritious foods are considered high-carb.

Oranges are high in good-for-you vitamin C, but they aren't keto-friendly.Joe St.Pierre Photography/Stocksy

The keto diet is known for its extremes. “By nature, the keto diet isn’t fully balanced,” says Keri Glassman, RD, a nutritionist in New York City. Just look at the ratios in a usual keto diet food list: People on a keto diet aim to eat upwards of 80 percent of their calories from fat. They’ll also eat very few carbs. So, for the most part, you’ll skip out on fruits, legumes (like beans and lentils), most dairy, starchy vegetables, and whole grains.

And while you don’t need fruit alone or beans alone to be healthy, when taken altogether and eliminating multiple foods, you can wind up with a less-than-nutritious diet.

Because of keto's restrictions, often patients on the diet are at risk for deficiencies in essential nutrients, like B vitamins (including B12), vitamin D, calcium, selenium, magnesium, and vitamin C, says Dana Elia, RDN, an integrative and functional medicine dietitian in Lancaster, Pennsylvania.

B12 is especially surprising because it’s in animal products, and those on a keto diet are typically consuming meat. But if you were consuming a standard American diet, which is typically filled with processed foods, you may have come to the keto diet already deficient in B12 (along with a slew of other nutrients), according to the Environmental Working Group. (Taking acid-suppressing medication may also impact B12 levels, Elia says.) On keto, this may remain a concern for you. To cover your nutrient bases, talk to a registered dietitian knowledgeable in keto before starting.

Also, know that keto isn’t just about avoiding refined grains, junk food, and sugar — a popular misconception. Everything except for pure fats (like oil) and meat (chicken, fish, beef) has a source of carbs. And while everyone’s carb allotment is different — often the recommendation is to stick to 20 to 50 grams (g) of net carbs (total carbs minus fiber, sugar alcohol, and glycerine) per day to stay in ketosis, or the state where you’re burning fat for fuel — some food that’s conventionally thought of as healthy won’t fit into a keto eating plan.

Here are 10 foods most people on keto will avoid:

1. Quinoa

Whole-grain quinoa may be protein-rich, but that doesn’t mean it fits with keto. A ½-cup serving contains 17 g of net carbs, which can easily eat up your carb budget.

2. Apples

An apple a day may keep the doctor away, but it really has no place on a keto diet. One medium apple has more than 20 g of net carbs — enough to blow someone’s entire carb allotment for the day. Especially if you’re someone who likes sweet, it’s unfortunate to kick out most fruit, but you can get these nutrients from a veggie-rich diet, says Glassman.

RELATED: 10 High-Fiber Foods to Add to Your Diet

3. Black Beans

Legumes — like beans and lentils — are pretty much off limits. That’s unfortunate. “Legumes are loaded with fiber and antioxidants,” says Glassman. While they may offer an impressive source of digestion-friendly fiber, black beans pack about 12 g of net carbs in just ½ cup. “You’ll want to make sure to get fiber elsewhere in your diet,” she says.

4. Dark Chocolate

One of the most dietitian-recommended desserts, dark chocolate, is a keto no-no. A 1-ounce (oz) serving has 10 g of net carbs. For people who are sticking to 20 g of net carbs a day, the small chocolate square would use up one-half of those.

5. Sweet Potatoes

It may be obvious that white potatoes are too starchy to fit on keto, but so, too, are sweet taters, no matter how you prep them. One medium-sized spud supplies 23 g of net carbs. Say goodbye to sweet potato toast.

6. Yogurt

Even whole milk yogurt can be the tipping point into too many carbs. One 8-oz container has 10 g of carbs. (Sweetened versions will have even more.) If you want a yogurt fix, stick to a small amount of plain, full-fat Greek yogurt. A ½-cup serving of Fage Total 5 percent, for instance, has 3.5 g of carbs.

7. Oranges

Avoiding orange juice because it’s too high in sugar? Good call. But that means oranges have to go, too. Just a small fruit alone has 13 g of net carbs.

8. Acorn Squash

Yep, even when you’re in full-on fall mode, nix squash from your dinner menu. One cup of baked acorn squash cubes may have 9 g of fiber, but it also contains 20 g of net carbs. For most people on a keto diet, that’s just too high.

9. Chickpeas

Roasted chickpeas may be a favorite trendy snack, but they probably won’t fit on keto. A ½-cup serving contains nearly 13 g of net carbs. Hummus is a better choice, with around 3 g of net carbs per 2-tbsp serving. Just stick to dipping in cucumbers and celery — not carrots.

10. Brown Rice

You may have already sworn off white rice, but add brown rice to that list, too. It’s a whole grain, which disqualifies it from a keto eating plan. Add a ½-cup serving to a roasted veggie bowl and you’re looking at 24 g of net carbs.