You probably already know that baked goods, candy, and most fruits are off the table on a ketogenic diet, but you’d think good ol’ veggies, which are typically low in carbs and pack a ton of nutrition, would be safe, right? Well…
Every rule has an exception, and while pretty much all of your favorite green veggies are keto-friendly, some higher-carb vegetables—like potatoes, carrots, and beets—are questionable.
A successful keto diet often requires cutting carbs down to just 50 grams total per day, or about 20 to 30 grams of net carbs (total carbs minus the fiber, which doesn’t raise your blood sugar). Just a serving of starchier vegetables, which are higher in net carbs than other vegetables (think: green) can potentially derail a keto diet and switch the body right back into burning sugar instead of fat, explains Ginger Hultin, M.S., R.D.N., C.S.O., spokesperson for the Academy of Nutrition and Dietetics.
While these seven higher-carb veggies are healthy, experts recommend avoiding them if you’re aiming for ketosis.
One medium potato contains 32 grams of net carbs, making the starchy root vegetable a pretty dangerous keto saboteur. “Potatoes are full of carbohydrates, which are turned to blood glucose [a.k.a. sugar] when broken down in the gut,” reinforces Mariana Daniela Torchia, Ph.D., R.D., M.P.H. Sweet potatoes, though high in antioxidants, are in the same boat.
Try swapping cauliflower, which contains just three grams of net carbs per serving, in for potatoes. The low-carb veggie has a mild, easy-to-spice-up flavor, and makes a great substitute for the tubers in your go-to mashed potato recipe. If you’re itching for the sweetness of sweet potatoes, Hultin recommends serving up zucchini or spaghetti squash, which also taste slightly sweet but contain just 2.7 and 5.5 grams of net carbs, respectively.
Peas may be green, but that doesn’t mean they’re in the same category as keto-friendly broccoli and romaine lettuce. Green peas are higher in net carbs, containing nearly 15 grams per one-cup serving, says Hultin.
Though carrots are a nutrient-dense root vegetable and provide your body with a hefty dose of beta-carotene, they walk a fine line when it comes to keto. One medium carrot contains about seven grams of carbohydrates, so they need to be carefully limited—or avoided—on a ketogenic diet, says Elizabeth Ann Shaw, M.S., R.D.N., C.L.T., C.P.T., who typically recommends the keto diet for those with specific medical concerns, not the average Joe.
If carrots are your usual veggie dipper of choice, try lower-carb zucchini spears, cucumbers, or bell peppers the next time you snack.
Before you add corn to your next batch of guacamole (the ultimate keto snack) or Mexican-style bowl meal, consider yourself warned: A small ear of corn packs a whopping 20 grams of carbs, making the sweet summertime staple pretty difficult to incorporate into a keto lifestyle.
Noticing a trend with the root vegetables yet? Beets are beautiful, incredibly healthy, and unfortunately, higher in sugar and carbs than most veggies that grow above ground. One cup contains about 10 grams of net carbs (nine from sugar).
You do have a root veggie option though: turnips, which contain fewer than eight grams of net carbs per serving. Hultin likes roasting them in olive oil, salt, and pepper for a side dish or snack.
6. Celeriac Root
Soups and stews can be easy staple meals on a keto diet—as long as you’re careful about the types of vegetables you throw into the pot.
Like many root vegetables, celeriac root (a common soup ingredient that’s related to celery) is higher in net carbs, and racks up about 12 grams per serving.
Hultin recommends using celery stalks and seasoning in soups to achieve the same flavor without sacrificing so many carbs.
Beans, which are often categorized as both proteins and vegetables, are a unique, nutrient-dense category of plants. Though they’re high in fiber, they’re also pretty high in carbs.
Most beans—including black beans, chickpeas, kidney beans, navy beans, and pinto—contain about 12 grams of net carbs (or more) per half-cup serving, says Hultin. Your best bean option: green beans, which contain fewer than five grams of net carbs per serving.