table of contents
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
The keto diet has become a popular eating plan for its reported health, wellness, and weight management benefits. However, accurately following a keto diet can be tricky because accurate macro counting is essential to reaching ketosis.
This article will define what the keto diet is and 12 keto-friendly food options. Before starting any new eating plan, speak with your healthcare provider to make sure it’s a healthy and sustainable option for you.
What is the keto diet?
The ketogenic diet is a very low-carb, high-fat diet designed to force your body to create energy using a different type of metabolism than usual. The body usually uses carbohydrates as its main source of energy, but when carbs are limited, it turns to a process called ketosis to create energy for the brain and central nervous system (CNS).
When you eat fewer than 50 grams of carbs per day your glucose stores, called glycogen, deplete. When this happens, your body will either use protein (through gluconeogenesis) or fat (through ketogenesis) to create energy (Masood, 2021).
During ketogenesis, ketone bodies are created. The ketone bodies provide energy to the brain and CNS while in ketosis.
You can check if you’re in ketosis by testing the level of ketones in your blood or urine. Home testing kits are available to check this. Ketone levels between 0.5 to 3 mg/dL indicate ketosis (Gershuni, 2018).
When following a keto diet, calculating your macronutrients—fat, carbs, and protein—is essential for helping you to stay in ketosis. In the standard ketogenic diet, the percentages of total calories from each nutrient are (Shilpa, 2018):
Some people may develop flu-like symptoms while their body adjusts to being in ketosis. These symptoms are called the keto flu, even though it isn’t a true flu. The keto flu is poorly understood, and it doesn’t affect everyone who starts a keto diet.
Here are some of the symptoms of the keto flu:
- Nausea and vomiting
- Constipation and diarrhea
- Irritability and difficulty concentrating
- Muscle cramps and soreness
- Trouble sleeping
- Sugar cravings
Why do people follow a ketogenic diet?
The keto diet was initially created as a treatment for epilepsy, a condition that causes recurrent seizures. Today it’s still used to help reduce the number and severity of seizures, especially in people for whom anti-seizure medications are less effective (Masood, 2021).
Over the past couple of decades, the keto diet has grown in popularity for other uses. There is conflicting research on the long-term effectiveness and safety of the keto diet. Still, there is some evidence of short-term benefits.
Possible health benefits of the keto diet include:
- Weight management: Research suggests following a ketogenic diet may help people lose weight quickly and sustainably (Masood, 2021). However, if weight loss is not one of your goals, it’s also possible to maintain your current weight on the keto diet—as long as you’re eating enough calories to maintain your current weight.
- Better blood sugar control: The keto diet may help people with type 2 diabetes reduce their hemoglobin A1C (a marker of how well their blood glucose is controlled over time) and keep their blood sugar levels more stable (Batch, 2020).
- Improved insulin resistance: Studies show a keto diet may improve insulin sensitivity and decrease the need for diabetes medication (Gershuni, 2018).
- Heart health: A meta-analysis found that following a low-carbohydrate diet may improve cardiovascular risk factors like cholesterol levels (Dong, 2020).
More long-term studies are needed to understand both the benefits and side effects of following a keto diet.
Is keto safe? Is it healthy?
Foods and drinks good for a keto diet
Ideally, when following a keto diet, most of the food you eat will be high in fat, with some good protein sources in the mix. The carb foods you eat should be high in fiber and low in total carbs (think lettuce, broccoli, and cauliflower).
Here are some of the foods often recommended for a keto diet:
Avocados are an excellent option for a keto diet because they are high-fat and low in net carbs. One whole avocado (about 136 g) provides about 227 calories, 3 grams of protein, 21 grams of fat, 11 grams of carbohydrate, and 9 grams of fibers. Avocados’ net carbs (total carbs minus fiber) is about 2 grams (USDA, 2019-a).
2. Full-fat cheese
Cheeses made with full-fat dairy are typically high in fat with some protein and minimal carbohydrates. Avoid choosing low-fat dairy products while following keto because, with keto, high fat is the goal.
Here are some types of cheeses that are low in carbs:
- Blue cheese
- Colby jack
- Cream cheese
- Pepper jack
3. Red meats
Beef and pork are staple foods for a keto diet. There are no carbs in these foods. Red meat is rich in high-quality protein, fat, B-vitamins, iron, and several other nutrients (USDA, 2019-b).
If your goal with the keto diet is weight loss, eating enough protein can help minimize muscle loss while maximizing fat loss (Cava, 2017).
Fatty fish is a good addition to a keto diet because it’s full of omega-3 fatty acids that are good for heart health (Jain, 2015). Since red meats, which contain less healthy omega-6 fatty acids, are a staple in the keto diet, it’s important to add fatty fish to balance out those fatty acids. Excessive omega-6 intake may increase inflammation, while omega-3s help reduce inflammation (Innes, 2018).
Consider adding fatty fish to your diet to balance your ratio of omega-6s to omega-3s. Fatty fish options include:
Chicken and turkey are two more staples in the keto diet because they have no carbs, are high in protein, and have less saturated fat than red meat. The white meat on birds is lower in fat, while the darker meat is high in saturated fat.
Be sure to avoid any breading on your meats since this will add carbs to them.
7 best diets for weight loss: what works?
Eggs are versatile and ideal for the ketogenic diet. One large whole egg contains about 143 calories, 12 grams of protein, 10 grams of fat, and less than 1 gram of carbs. Egg yolks are rich in lutein, zeaxanthin, choline, and other vitamins (USDA, 2019-c).
Olive oil and coconut oil are both high in healthy fats. Olive oil contains mostly unsaturated fat and antioxidants like phenols and vitamin E. It’s ideal for cooking, salad dressings, mayonnaise, and adding to foods to increase calories or fat content.
Coconut oil contains more saturated fat and a type of fat called medium-chain triglycerides (MCTs). MCTs are more easily converted to ketones by the liver, so they’re easier to use for energy than other types of fat.
8. Full-fat, plain yogurt and cottage cheese
Full-fat varieties of plain yogurt and cottage cheese are usually lower in carbohydrates while being good sources of fat and protein. Even though both do contain some carbs, they can be great snacks on the keto diet.
Try combining them with spices like cinnamon or top with nuts for a delicious keto snack.
9. Nuts and seeds
Both nuts and seeds are full of vitamins and minerals. Most varieties are lower in net carbs while providing dietary fat and protein. Regularly eating nuts has been associated with a lower risk for heart disease and stroke (Guasch-Ferre, 2017).
Here is a list of nuts and seeds ideal for a keto eating plan:
- Pumpkin seeds
- Chia seeds
- Macadamia nuts
- Nut butters (peanut butter, almond butter, etc.)
Keto snacks: what are they and are they healthy?
10. Non-starchy vegetables
Veggies are one of the food types that provide carbohydrates, but the amount of net carbs depends if they are starchy or non-starchy vegetables. Potatoes, green peas, parsnips, corn, and other starchy vegetables are higher in carbs, which don’t work well for a keto diet. Instead, a keto diet calls for vegetables high in fiber and keeping the total net carbs low.
Some of the best vegetables for keto include:
- Brussels sprouts
- Green beans
- Bell pepper
- Spinach and other leafy greens
The majority of fruits are too high in net carbs to regularly consume while following a keto diet. The exception is berries because they are lower in carbs and high in fiber. Blueberries, raspberries, strawberries, and blackberries can all be enjoyed occasionally while following a keto diet.
12. Unsweetened beverages
Coffee, tea, water, and carbonated waters can all be enjoyed on the keto diet. When unsweetened, these contain less than 1 gram of carbs per cup. You could consider adding stevia to your coffee or tea if you’re looking for a bit of sweetness in your drink.
What foods to avoid on the keto diet?
When following a keto diet, you want to avoid or limit high carb foods, such as:
Processed snacks and desserts
Any foods processed with added sugar will increase your carb intake and keep you out of ketosis. Candy, cookies, bread, pastries, sweetened greek yogurt, ice cream, bagels, maple syrup, agave, and other sugary foods aren’t good options for a keto meal plan.
Even condiments and sauces may be too high in carbs, such as ketchup, pasta sauce, and salad dressings. Pay attention to food labels to see if something is a good option for your keto diet plan.
All starchy foods convert to glucose during digestion. Even though some varieties, like oats, are high in fiber, the total carbohydrates are still too high for the keto diet’s requirements. Starchy foods to avoid include bread, tortillas, chips, pasta, rice, quinoa, legumes, lentils, oatmeal, and sweet potatoes.
Keto pills: here’s what the research has to say
Most varieties of fruit (except berries) are too high in carbs for the keto diet plan. So despite the many health nutrients in fruit, while following a keto diet, it’s best to avoid eating them.
Sweet tea, sports drinks, soda, and sweetened coffee are loaded with added sugar and sweeteners. Instead of these, try to drink unsweetened coffee, tea, and sparkling water. It’s a good idea to drink plenty of regular water while following a keto diet to stay hydrated.
Many types of alcohol need to be limited on the keto diet. Most types of beer and wine are too high in carbs. If you choose to drink alcohol while following keto, consider dry wine, spirits, or hard seltzers in moderation. Always talk with your healthcare provider or consult with a dietitian before making big diet changes to better understand how they will impact your health and if it’s the right fit for you. It can be tricky to follow a keto diet, so support may help you find a good long-term option for you.
- Batch JT, Lamsal SP, Adkins M, Sultan S, & Ramirez MN. (2020). Advantages and disadvantages of the ketogenic diet: a review article. Cureus, 12(8), e9639. doi: 10.7759/cureus.9639. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7480775/
- Cava E, Yeat NC, & Mittendorfer B. (2017). Preserving healthy muscle during weight loss. Advances in Nutrition, 8(3), 511–519. doi: 10.3945/an.116.014506. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28507015/
- Masood W, Annamaraju P, Uppaluri KR. (2021). Ketogenic diet. In: StatPearls [Internet]. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK499830/
- Dong T, Guo M, Zhang P, Sun G, & Chen B. (2020). The effects of low-carbohydrate diets on cardiovascular risk factors: a meta-analysis. PloS One, 15(1), e0225348. doi: 10.1371/journal.pone.0225348. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6959586/
- Guasch-Ferré M, Liu X, Malik VS, Sun Q, Willett WC, Manson JE, et al. (2017). Nut consumption and risk of cardiovascular disease. Journal of the American College of Cardiology, 70(20), 2519–2532. doi: 10.1016/j.jacc.2017.09.035. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29145952/
- Gershuni VM, Yan SL, & Medici V. (2018). Nutritional ketosis for weight management and reversal of metabolic syndrome. Current Nutrition Reports, 7(3), 97–106. doi: 10.1007/s13668-018-0235-0. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6472268/
- Innes JK, Calder PC. (2018). Omega-6 fatty acids and inflammation. Prostaglandins, Leukotrienes, and Essential Fatty Acids, 132, 41–48. doi: 10.1016/j.plefa.2018.03.004. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29610056/
- Jain AP, Aggarwal KK, & Zhang PY. (2015). Omega-3 fatty acids and cardiovascular disease. European Review for Medical and Pharmacological Sciences, 19(3), 441–445. Retrieved from https://pubmed.ncbi.nlm.nih.gov/25720716/
- Shilpa J, & Mohan V. (2018). Ketogenic diets: boon or bane?. The Indian Journal of Medical Research, 148(3), 251–253. doi: 10.4103/ijmr.IJMR_1666_18. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6251269/
- USDA. (2019-a). Avocados, raw, California. Retrieved from https://fdc.nal.usda.gov/fdc-app.html#/food-details/171706/nutrients
- USDA. (2019-b). Beef, grass-fed, ground, raw. Retrieved from https://fdc.nal.usda.gov/fdc-app.html#/food-details/168608/nutrients
- USDA. (2019-c). Eggs, grade a, large, egg whole. Retrieved from https://fdc.nal.usda.gov/fdc-app.html#/food-details/748967/nutrients
Dr. Steve Silvestro is a board-certified pediatrician and Senior Manager, Medical Content & Education at Ro.