15 Foods You Can’t Eat on Keto (and What to Choose Instead)
From traditionally healthy foods to not-so-nutritious eats, these options can stymie keto success. Make the following swaps to stay on track.
Nonstarchy veggies should be staples for anyone on a keto diet.
If you’re thinking about embarking on a ketogenic diet, you probably already know you’re going to be avoiding sources of processed grains and sugar, like pizza and muffins. After all, it’s an extremely low-carb, high-fat diet, and those are two of the more obvious carbohydrate culprits. But many of the foods you’ll also avoid aren’t necessarily unhealthy. In fact, many “no” foods are packed with health-promoting vitamins, minerals, and fiber but offer a rich source of carbs that doesn’t work on a really low-carb plan — especially one as restrictive as the keto diet.
Many people following keto aim for 20 to 50 grams (g) of net carbohydrates per day. (Net carbs, though not an official nutrition term, can be calculated by taking the total carbohydrates minus fiber and sugar alcohols, per Atkins.com.) The idea is to switch your body into ketosis, a state where it burns fat for fuel rather than carbohydrates (its preferred and easy-to-access source of energy). As such, some of your favorites, including many fruits, whole grains, and some vegetables, now must be drastically limited.
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That said, not everyone should embark on a keto diet. “For some people, the keto diet can be harmful,” says Stephen Herrmann, PhD, senior director of research and innovation for Profile Sanford, a division of Sanford Health, a health system based in Sioux Falls, South Dakota. That includes those people with type 2 diabetes who are on insulin and those who have type 1 diabetes and must take insulin, he says. If you have any chronic health condition that you’re hoping to, in part, treat with a keto diet, talk to your doctor first, who can best advise if this is a safe diet for you.
After you’ve gotten the all clear, planning your keto diet can go a long way in your success on it. Because of the low-carb requirements, it often helps to think about what foods are off-limits (or mostly off-limits) — and if this doesn’t seem realistic, you may want to rethink going keto.
Here are 15 foods — some healthy, others not so much — that you should try to avoid on keto and what to choose instead.
Skip Croutons for Hemp Hearts in Your Salad
Sure, croutons are one way to make a pile of lettuce more interesting, but the reality is that on a keto diet, every crumb counts. According to the U.S. Department of Agriculture (USDA), only 2 tablespoons (tbsp) contain 5 g of net carbs, which will severely limit the other veggies and add-ons you can include.
Instead, add crunch with hemp hearts, says Bonnie Nasar, a registered dietitian nutritionist in Freehold, New Jersey. Not only are they more nutrient-dense than croutons in general, but you can pile on more for fewer carbs: 3 tbsp of hemp hearts have just 1.4 g of net carbs, according to the USDA. Bonus: Hemp hearts are a rich source of unsaturated fat that can help you meet your fat goals for the day.
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Bypass Starchy Peas and Opt for Broccoli as Your Veggie Side
Peas are a starchy vegetable that contains a higher amount of carbs compared with green nonstarchy veggies, such as broccoli or zucchini. That said, if you have eaten a bowl of them recently, don’t feel bad: “If the food you’re going overboard on is peas, it’s not the worst thing you can do” health-wise says Herrmann. Just know that because they have 14 g net carbs per cup, they’re likely to put you off track on keto.
Opt for those nonstarchier veggies. For instance, according to the USDA, broccoli contains 2.9 grams of net carbs per cup; zucchini has 2.6 grams of net carbs per cup; raw spinach has 0.4 grams of net carbs per cup. While you’re cutting carbs at this time, it’s important to use that allotment to eat high-fiber foods to help keep constipation, an unpleasant side effect of keto, at bay, says Nasar. Nonstarchy veggies are the best way to do this, as they offer the most fiber for the lowest amount of net carbs.
Low-Calorie Packs May Still Be High Carb — Choose Sunflower Seeds Instead
On keto, you’ll eat far more fresh foods than you did if you were on a standard American diet prior. (The U.S. Department of Health and Human Services notes that most Americans don’t eat enough fruits and veggies, and eat too many foods high in saturated fat, sodium, and added sugar.) Therefore, the days of focusing on fat-free — and carb-rich — snacks, like pretzels or 100-calorie packs of crackers, are over unless you’re noshing on keto-friendly packaged fare.
“People are used to eating what’s easy and right in front of them, but there are just as easy snacks readily available,” says Nasar. Those include sunflower seeds, toasted pumpkin seeds, and nuts.
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Potato Chips Aren’t Keto-Friendly, so Try This DIY Seaweed Snack
Likewise, potato chips are out, though you probably already guessed that. A 1-ounce (oz) serving (a measly 22 chips) has about 14 g of net carbs, per the USDA.
A worthy keto- and heart-friendly snack substitute to scratch the salty itch, says Nasar: Finely chop up nuts and seeds in a food processor, and add white vinegar and salt. Roll the mixture up in pieces of seaweed (like a cigar) and cook in the oven for 5 to 10 minutes until crispy.
Bananas Are Healthy but High Carb, Though Berries Can Work on Keto
According to the USDA, one small banana has more than 20 g of net carbs, which means you may blow your entire carb allowance on a single banana. “We advise people on a lower-carb diet to avoid bananas, particularly in the beginning and when they’re aiming to lose weight,” says Herrmann. If you increase your carb goals once you’ve lost weight and are in maintenance mode, you may opt to eat bananas occasionally.
If you want to eat fruit, berries are a lower carb choice. But you still have to keep portions low, as fruits are naturally higher in carbs. Raspberries are packed with fiber, making them a good go-to. Raspberries, for instance, contain 1.7 grams of net carbs per ¼ cup.
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Honey-Baked Ham Is Glazed in Sugar, Yet Deli Meat Can Be Compliant
When Nasar recommends the keto diet for folks, she suggests a Mediterranean keto diet, which leans heavily on plant foods. For that reason, while some processed meats are keto-friendly but may not be the most heart-healthy choice, like bacon, others may not be compliant at all with the diet. You’ll want to check the ingredients list first. One that you should avoid is glazed ham. It’s not only considered a processed meat but is also often cooked with a sugar topping. One serving (approximately 3.5 oz) contains 7.3 g of net carbs.
If you’re looking for ham, go for a traditional sliced ham deli meat, which has just 0.6 g of net carbs for the same serving size. Still, you’ll want to read the ingredients list to make sure it’s not made with added sugar.
Margarine Isn’t Keto-Friendly, so Opt for EVOO
Old stick margarines were rich in trans fats, which increased risk of heart disease, according to Harvard Health. Today, margarine spreads are made from oils like soybean, palm, or palm kernel, which are not recommended on a keto diet.
Nasar recommends using extra virgin olive oil because of the large amount of research that backs up olive oil’s heart-healthy properties. Olive oil is rich in monounsaturated fatty acids that temper inflammation and promote blood flow, notes a 2018 review in the journal Endocrine, Metabolic & Immune Disorders – Drug Targets.
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Piña Coladas Are Sugar Bombs — Sip on a Vodka Soda Instead
If you’re on the diet because you want to lose weight or it’s summer, Herrmann advises skipping alcohol entirely during this time. “The body chooses to metabolize alcohol first; that, along with a loss of water and micronutrients, increases the risk of dehydration,” he says. Yet if you choose to drink, the worst choice you can make are blended, frozen drinks, which are also packed with sugar — and thus carbohydrates. As an example, a piña colada has 43.7 grams of net carb per drink. For some people, that represents two days’ worth of their carb allotment.
When you’re on keto, you can drink small amounts of alcohol occasionally and in moderation. For the lowest number of carbs, choose a shot of hard liquor and pair it with unsweetened soda water. A vodka soda has zero carbs per drink.
Beer Is Packed With Carbs, but Light Beer in Moderation May Be Okay
And that includes many light beers, which generally pack 6 g of carbohydrates per can. In the context of keto, a beer means that you’re going to have to borrow carbohydrates elsewhere — and if it’s a matter of vegetables versus a beer, the tough — but necessary choice — is the veggies.
If you must have beer, you’ll have to choose your light beer wisely and drink less of it. Michelob Ultra offers minis, which are 8 oz cans that have 1.7 g of carbs.
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Sweet Potatoes Aren’t Okay on Keto, but Cauliflower Is
If you’ve tried Whole30 or a paleo diet, you may have eaten a lot of sweet potatoes, but it’s another starchy veggie that you should think twice about now on keto, says Herrmann. A medium sweet spud has about 20 g of carbs.
Cauliflower is a fine sub for sweet potatoes, as it’s frequently used as a replacement for other starchy foods. (Mash them with olive oil and garlic, and voilà!) One cup of cauliflower florets contains just 3.2 g of net carbs.
Cow’s Milk Is a Major Source of Carbs — Reach for Almond Milk Instead
Whole milk is richer in fat compared with reduced-fat or skim, but that doesn’t make it keto compliant. One cup of whole has 11.7 grams of net carbs. If you’re making a smoothie, this can derail your goals.
If you really need a liquid base for a smoothie or want to sip on something, go for almond milk. With 1 g of net carb per cup, you can make this nondairy alternative work in your keto diet. Just be sure to read the ingredients and choose an unsweetened variety.
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Trail Mix Is a No-No, While Raw or Salted Nuts Are Allowed on Keto
Check out what’s in your trail mix. Are there raisins and other dried fruit? Pretzel pieces? Chocolate candies? For that reason, trail mix is typically off-limits. A standard 1 oz serving (a small amount, by the way) has more than 12 g of carbs.
Plain or roasted salted nuts are great snack options. Nuts have carbs, but they are also a great source of fiber, which brings down their net carb count. One oz of almonds supplies 2.6 g of net carbs.
Carrots, Though Healthy, Are Starchier Than Other Veggies Like Bell Peppers
They may be packed with vision-friendly vitamin A, but one medium carrot has 5 g of carbs, per the USDA. You'll probably eat more than just a single carrot in a sitting, and that small number of carbs can easily tip you over the edge.
You’re better off getting your A through nonstarchy sources like bell peppers. These can be just as sweet as carrots but contain fewer carbohydrates. An entire small pepper has 2.9 g of net carbs, per the USDA.
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Soda Isn’t Allowed on Keto, but Unsweetened Sparkling Water Is a Great Choice
The keto diet often marks a drastic shift in eating habits. If you are a soda drinker, you’ll have to get it out of your diet completely, says Herrmann. It may be tough to do at first, but these are packed with sugar, and eating less of the sweet stuff will benefit your health, regardless of whether you’re on keto, he says. (Cola has 35 g of sugar per can.) In fact, drinking soda has been associated with greater odds of dying from cardiovascular disease, according to a March 2019 study in the journal Circulation. Ultimately, you’re making a march toward a healthier pattern of eating, so working with a registered dietitian who’s knowledgeable in the keto diet can help you figure out how to cut back and replace it in your diet.
Because it’s carb-free, diet soda is technically an okay option. But sparkling water is an even better choice when you want that fizz, since it doesn’t even contain the artificial sweeteners present in diet drinks. These sweeteners may stimulate appetite and increase the risk for weight gain, per a study published in March 2014 in the American Journal of Clinical Nutrition. Choose naturally flavored but unsweetened versions of sparkling water, like those from brands LaCroix or Waterloo. Both have zero grams of carbs.
Butternut Squash Is Too Starchy to Be Keto-Friendly, Yet Spaghetti Squash Is Okay
Butternut squash is another nutrient-packed veggie that offers just too many carbs than are likely comfortable for your diet. One cup of cubed squash has more than 13 g of net carbs. It’s always a bummer when foods that are nutrient rich (squash is rife with beta-carotene, according to Berkeley Wellness), versatile, and delicious are off-limits, but the reality of the keto diet is that it does eliminate some traditionally good-for-you foods.
Spaghetti squash can fit into your diet as long as you use small amounts. For instance, a ½-cup portion of cooked spaghetti squash as “noodles” amounts to 3.9 g of net carbs (sans sauce).