Lately it seems everyone is bidding farewell to grains, starchy vegetables, and sugar, and loading up on quality fats like coconut, olive oil, and avocado. The keto diet, which is all about shifting your body into ‘ketosis’—a state in which a complete lack of carbs forces you to utilize fat (including body fat) for energy—promises to eliminate cravings, stabilize blood sugar levels, increase energy levels, and support weight loss.
There’s a catch, though: Cutting out so many foods to keep carb intake low enough to get into (and stay in) ketosis can come with consequences. “The reduction of [starchy] veggies and near-elimination of fruits and grains can lead to problems getting some essential vitamins and minerals,” says Mike Israetel, Ph.D., chief sport scientist and co-founder of Renaissance Periodization, sports nutrition consultant for U.S. Olympic Sports and Team USA Weightlifting.
Of course, you’re more likely to fall short on important nutrients if your version of keto consists of just buttery Bulletproof coffee, bacon, and cheese. However, even the healthiest keto diet (think meals like salmon with asparagus and spinach sautéed in olive oil, and lots of leafy greens and cruciferous veggies) can leave your body wanting.
With grains and starchy vegetables off the table, many keto dieters end up falling short on their fiber needs, says dietitian Kristen Mancinelli, M.S., R.D.N., who specializes in low-carb diets and recommends keto eaters aim for 30 grams of fiber per day from vegetables, nuts, and seeds. Veggies like spinach, collard greens, cauliflower, and broccoli are all great choices because they provide fiber without the extra carbs. Not only does fiber support healthy digestion, cholesterol, and blood sugar, but it’s also key for your immune function.
If you find yourself constipated, you have two tasks: First, make sure you’re staying adequately hydrated: Men should start with a baseline of 3.7 liters a day and women with 2.7 liters (more if you exercise or sweat throughout the day). Second, try a fiber supplement. Most provide about five grams of fiber per serving; just look for one with fewer than two grams of net carbs (carbs minus fiber), like The Vitamin Shoppe brand Miracle Fiber.
Ketosis causes excess urination, because your body releases water as you slash carbs. Without carbs in your diet, you burn through your body’s stores of glycogen (a form of sugar we make from carbs). Since that glycogen also stores water, you’ll pee out extra water—along with some of your electrolyte (sodium, potassium, and magnesium) stores—as you transition into ketosis.
Your body needs electrolytes for everything from cellular function, heart muscle contractions, and neurological impulses, so it’s essential that you maintain the proper levels. If you notice issues like muscle cramps, fatigue and nausea—especially in the beginning stages of your keto journey—you could be dealing with an electrolyte imbalance and may need to add a supplement.
Sodium: Keto eaters need to consume more sodium than the average person, so Mancinelli recommends upping your sodium intake to between 2.5 and three grams per day. (The usual allowance is up to 2.3 grams per day.) Fill your trusty salt shaker with pink Himalayan sea salt, which contains minerals and trace elements, and sprinkle away!
Magnesium: Most people don’t eat the recommended amount of magnesium per day (about 400 milligrams for men and 300 for women), and keto eaters are certainly no exception. Mancinelli recommends supplementing with between 200 and 400 milligrams per day.
Potassium: This is another mineral most people fall short on (we need 4,700 milligrams per day), and going keto makes that even more likely by pretty much banning potassium-rich foods like bananas, sweet potatoes, and beans.
Supplementing with potassium can potentially be dangerous, so Mancinelli recommends keto eaters show their electrolyte levels some love with a combo supplement that provides more moderate amounts of each mineral, like Country Life’s Calcium Magnesium Potassium tablets, which provides 500 milligrams of magnesium and 99 milligrams of potassium. Electrolyte drink mixes—like BodyTech’s Electrolyte Fizz—are another convenient way to add more of these important minerals to your day.
A ketogenic diet that’s heavy in animal products (and the saturated fat they contain) can have a negative impact on cholesterol, according to Mancinelli. That’s why she recommends keto dieters supplement with omega-3s—especially if you’re not a big fish eater. The two most important omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), support heart health and healthy cholesterol. Most supplements come in the form of fish oil and provide about 1,000 milligrams per serving. Nordic Naturals’ Ultimate Omega provides 1,280 milligrams and tastes like lemons.
While there aren’t set recommendations for our daily intake of phytochemicals (the health-boosting compounds found in plant foods), there are recommendations for fruits and veggies: A cup and a half of fruit plus two cups of veggies a day for women, and two cups of fruit plus two and a half cups of veggies a day for men.
No, there’s no true replacement for fruits and veggies, but fruit and greens powders, which are made from a variety of fruits and/or vegetables that are dried and ground—can help you increase your phytochemical intake and round out your overall nutrition, says Israetel. You can add them to keto-friendly smoothies or just mix them with water or protein for a boost of plant-based nutrition throughout the day. Two popular options: Garden of Life’s Raw Organic Perfect Food Green Superfood in Chocolate Cacao and plnt’s Organic BioGreens.