The ketogenic diet, or keto diet, is a very low-carb, high-fat diet that shares many similarities with the Atkins and low-carb diets. It involves drastically reducing carbohydrate intake and replacing it with fat. This reduction in carbs puts your body into a metabolic state called ketosis. When this happens, your body becomes incredibly efficient at burning fat for energy. It also turns fat into ketones in the liver, which can supply energy for the brain. Ketogenic diets can cause significant reductions in blood sugar and insulin levels. This, along with the increased ketones, has some health benefits.
Keto Basics
The ketogenic diet is a well-known low-carb diet where the body produces ketones in the liver to be used as energy. Since glucose is typically used as the primary energy source, fats are not needed and are therefore stored. On a normal, higher carbohydrate diet, the body will use glucose as the main form of energy. Ketosis is a natural process the body initiates to help us survive when food intake is low. The end goal of a properly maintained keto diet is to force your body into this metabolic state. Our bodies are incredibly adaptive to what you put into them - when you overload them with fats and take away carbohydrates, they will begin to burn ketones as the primary energy source. Optimal ketone levels offer many health, weight loss, physical, and mental performance benefits.
Types of Ketogenic Diets
There are several versions of the ketogenic diet, and what you eat depends on the type. They include:
- Standard ketogenic diet (SKD): This is a very low carb, moderate protein, and high-fat diet. It typically contains 70% fat, 20% protein, and only 10% carbs.
- Cyclical ketogenic diet (CKD): This diet involves periods of higher carb refeeds, such as 5 ketogenic days followed by 2 high carb days.
- Targeted ketogenic diet (TKD): This diet allows you to add carbs around workouts.
- High protein ketogenic diet: This is similar to a standard ketogenic diet but includes more protein. The ratio is often 60% fat, 35% protein, and 5% carbs.
However, only the standard and high protein ketogenic diets have been studied extensively. Cyclical or targeted ketogenic diets are more advanced methods and primarily used by bodybuilders or athletes. The information in this article mostly applies to the standard ketogenic diet (SKD), although many of the same principles also apply to the other versions.
Understanding Ketosis
Ketosis is a metabolic state in which your body uses fat for fuel instead of carbs. It occurs when you significantly reduce your consumption of carbohydrates, limiting your body’s supply of glucose (sugar), which is the main source of energy for the cells. Following a ketogenic diet is the most effective way to enter ketosis. Generally, this involves limiting carb consumption to around 20 to 50 grams per day and filling up on fats, such as meat, fish, eggs, nuts, and healthy oils. It’s also important to moderate your protein consumption. This is because protein can be converted into glucose if consumed in high amounts, which may slow your transition into ketosis.
Read also: Easy Low-Carb Cheese Crackers
Practicing intermittent fasting could also help you enter ketosis faster. There are many different forms of intermittent fasting, but the most common method involves limiting food intake to around 8 hours per day and fasting for the remaining 16 hours. Blood, urine, and breath tests are available, which can help determine whether you’ve entered ketosis by measuring the number of ketones produced by your body. Certain symptoms may also indicate that you’ve entered ketosis, including increased thirst, dry mouth, frequent urination, and decreased hunger or appetite.
Benefits of the Keto Diet
A ketogenic diet is an effective way to lose weight and lower risk factors for disease. In fact, research shows that the ketogenic diet may be as effective for weight loss as a low-fat diet. What’s more, the diet is so filling that you can lose weight without counting calories or tracking your food intake. One review of 13 studies found that following a very low carb, ketogenic diet was slightly more effective for long-term weight loss than a low-fat diet. People who followed the keto diet lost an average of 2 pounds (0.9 kg) more than the group that followed a low-fat diet. Another study in 34 older adults found that those who followed a ketogenic diet for 8 weeks lost nearly five times as much total body fat as those who followed a low-fat diet. The increased ketones, lower blood sugar levels, and improved insulin sensitivity may also play a key role.
Keto and Diabetes
Diabetes is characterized by changes in metabolism, high blood sugar, and impaired insulin function. One older study found that the ketogenic diet improved insulin sensitivity by a whopping 75%. A small study in women with type 2 diabetes also found that following a ketogenic diet for 90 days significantly reduced levels of hemoglobin A1C, which is a measure of long-term blood sugar management. Another study in 349 people with type 2 diabetes found that those who followed a ketogenic diet lost an average of 26.2 pounds (11.9 kg) over a 2-year period. What’s more, they also experienced improved blood sugar management, and the use of certain blood sugar medications decreased among participants throughout the course of the study.
Other Health Benefits
Studies have now shown that the diet can have benefits for a wide variety of different health conditions:
- Heart disease: The ketogenic diet can help improve risk factors like body fat, HDL (good) cholesterol levels, blood pressure, and blood sugar.
- Cancer: The diet is currently being explored as an additional treatment for cancer, because it may help slow tumor growth.
- Alzheimer’s disease: The keto diet may help reduce symptoms of Alzheimer’s disease and slow its progression.
- Epilepsy: Research has shown that the ketogenic diet can cause significant reductions in seizures in epileptic children.
- Parkinson’s disease: Although more research is needed, one study found that the diet helped improve symptoms of Parkinson’s disease.
- Polycystic ovary syndrome: The ketogenic diet can help reduce insulin levels, which may play a key role in polycystic ovary syndrome.
- Brain injuries: Some research suggests that the diet could improve outcomes of traumatic brain injuries.
However, keep in mind that research into many of these areas is far from conclusive.
Read also: Keto Calorie Counting: A Detailed Guide
Foods to Avoid on a Keto Diet
Here’s a list of foods that need to be reduced or eliminated on a ketogenic diet:
- Sugary foods: Soda, fruit juice, smoothies, cake, ice cream, candy, etc.
- Grains or starches: Wheat-based products, rice, pasta, cereal, etc.
- Fruit: All fruit, except small portions of berries or strawberries
- Beans or legumes: Peas, kidney beans, lentils, chickpeas, etc.
- Root vegetables and tubers: Potatoes, sweet potatoes, carrots, parsnips, etc.
- Low fat or diet products: Low fat mayonnaise, salad dressings, and condiments
- Some condiments or sauces: Barbecue sauce, honey mustard, teriyaki sauce, ketchup, etc.
- Unhealthy fats: Processed vegetable oils, mayonnaise, etc.
- Alcohol: Beer, wine, liquor, mixed drinks
- Sugar-free diet foods: Sugar-free candies, syrups, puddings, sweeteners, desserts, etc.
Foods to Eat on a Keto Diet
You should base the majority of your meals around these foods:
- Meat: Red meat, steak, ham, sausage, bacon, chicken, and turkey
- Fatty fish: Salmon, trout, tuna, and mackerel
- Eggs: Pastured or omega-3 whole eggs
- Butter and cream: Grass-fed butter and heavy cream
- Cheese: Unprocessed cheeses like cheddar, goat, cream, blue, or mozzarella
- Nuts and seeds: Almonds, walnuts, flaxseeds, pumpkin seeds, chia seeds, etc.
- Healthy oils: Extra virgin olive oil, and avocado oil
- Avocados: Whole avocados or freshly made guacamole
- Low carb veggies: Green veggies, tomatoes, onions, peppers, etc.
- Condiments: Salt, pepper, herbs, and spices
It’s best to base your diet mostly on whole, single-ingredient foods.
Sample Keto Meal Plan
Here is a sample keto meal plan for a week:
Monday
- Breakfast: Veggie and egg muffins with tomatoes
- Lunch: Chicken salad with olive oil, feta cheese, olives, and a side salad
- Dinner: Salmon with asparagus cooked in butter
Tuesday
- Breakfast: Egg, tomato, basil, and spinach omelet
- Lunch: Almond milk, peanut butter, spinach, cocoa powder, and stevia milkshake with a side of sliced strawberries
- Dinner: Cheese-shell tacos with salsa
Wednesday
- Breakfast: Nut milk chia pudding topped with coconut and blackberries
- Lunch: Avocado shrimp salad
- Dinner: Pork chops with Parmesan cheese, broccoli, and salad
Thursday
- Breakfast: Omelet with avocado, salsa, peppers, onion, and spices
- Lunch: A handful of nuts and celery sticks with guacamole and salsa
- Dinner: Chicken stuffed with pesto and cream cheese, and a side of grilled zucchini
Friday
- Breakfast: Sugar-free Greek, whole milk yogurt with peanut butter, cocoa powder, and berries
- Lunch: Ground beef lettuce wrap tacos with sliced bell peppers
- Dinner: Loaded cauliflower and mixed veggies
Saturday
- Breakfast: Cream cheese pancakes with blueberries and a side of grilled mushrooms
- Lunch: Zucchini and beet “noodle” salad
- Dinner: White fish cooked in olive oil with kale and toasted pine nuts
Sunday
- Breakfast: Fried eggs with mushrooms
- Lunch: Low carb sesame chicken and broccoli
- Dinner: Spaghetti squash Bolognese
Always try to rotate the vegetables and meat over the long term, as each type provides different nutrients and health benefits.
Read also: Magnesium Supplements for Keto
Keto Diet When Eating Out
When eating out, select a meat-, fish-, or egg-based dish. Order extra veggies instead of carbs or starches, and have cheese for dessert. At Mexican restaurants, you can enjoy any type of meat with extra cheese, guacamole, salsa, and sour cream. For dessert, ask for a mixed cheese board or berries with cream. Add extra avocado, cheese, bacon, or eggs. Another favorite is bun-less burgers. You could also swap the fries for vegetables instead.
Side Effects and How to Minimize Them
Although the ketogenic diet is usually safe for most healthy people, there may be some initial side effects while your body adapts. There’s some anecdotal evidence of these effects often referred to as the keto flu. Based on reports from some on the eating plan, it’s usually over within a few days. Reported keto flu symptoms include diarrhea, constipation, and vomiting. Other less common symptoms include poor energy and mental function, increased hunger, sleep issues, nausea, digestive discomfort, and decreased exercise performance.
To minimize this, you can try a regular low carb diet for the first few weeks. This may teach your body to burn more fat before you completely eliminate carbs. A ketogenic diet can also change the water and mineral balance of your body, so adding extra salt to your meals or taking mineral supplements may help. Talk to your doctor about your nutritional needs. At least in the beginning, it’s important to eat until you’re full and avoid restricting calories too much. Usually, a ketogenic diet causes weight loss without intentional calorie restriction.
Long-Term Considerations and Potential Risks
While the keto diet has its benefits, staying on it in the long term may have some negative effects, including risks of the following:
- Low protein in the blood
- Extra fat in the liver
- Kidney stones
- Micronutrient deficiencies
A type of medication called sodium-glucose cotransporter 2 (SGLT2) inhibitors for type 2 diabetes can increase the risk for diabetic ketoacidosis, a dangerous condition that increases blood acidity. Anyone taking this medication should avoid the keto diet. More research is being done to determine the safety of the keto diet in the long term. Keep your doctor informed of your eating plan to guide your choices.
Helpful Supplements
Although no supplements are required, some can be useful.
- MCT oil: Added to drinks or yogurt, MCT oil provides energy and helps increase ketone levels.
- Minerals: Added salt and other minerals can be important when starting out due to shifts in water and mineral balance.
- Caffeine: Caffeine can have benefits for energy, fat loss, and performance.
- Exogenous ketones: This supplement may help raise the body’s ketone levels.
- Creatine: Creatine provides numerous benefits for health and performance. This can help if you are combining a ketogenic diet with exercise.
- Whey: Use half a scoop of whey protein in shakes or yogurt to increase your daily protein intake.
Common Mistakes to Avoid on Keto
Avoid the following common pitfalls of keto to ensure you’re following this approach as safely as possible.
1. Cutting Your Carbs and Increasing Your Fat Too Quickly
One day you’re eating cereal, sandwiches, and pasta, and the next you decide to hop on keto and eat less than 50 grams (g) of carbohydrates a day, which is often the amount recommended at the beginning of keto, according to research published in Frontiers in Nutrition in July 2021. That may be a drastic change for your body. Consider easing in. Prior to starting a keto diet, individuals may benefit from tapering down their carbohydrate intake, instead of reducing carbs cold turkey.
2. Not Drinking Enough Water
For all the focus on what you’re eating, don’t forget about what you’re sipping. Dehydration is an increased possibility on keto. The drastic decrease in carbohydrate intake on the ketogenic diet can cause shifts in your fluid and electrolyte balance. Carbs are stored along with water in the body, so as these stores are depleted, that water is lost along with them. The body flushes out the buildup of ketones in urine, which also depletes water and sodium from the body. All that to say: Drink up. It's recommended waking up to a large glass of water and sipping regularly throughout the day to reach a goal of consuming half of your body weight numerically in ounces of water daily.
3. Not Preparing Yourself for the Keto Flu
As your body transitions from carbohydrate burner to fat burner, you may experience what’s known as the “keto flu,” or flu-like symptoms that begin shortly after you start the diet and that eventually go away. The exact reason why people may experience the keto flu isn’t known, according to Harvard Health. It doesn’t happen to everyone, FYI. But in a study published in the March 2020 Frontiers in Nutrition that analyzed online forums where people reported their keto flu symptoms, people described 54 different symptoms of the keto flu, most commonly headache, fatigue, nausea, dizziness, brain fog, GI distress, decreased energy, faintness, and changes in heartbeat, which started within several days of beginning keto, peaked after one week, and diminished after four weeks.
If you’re not prepared for this feeling, you may think something is drastically wrong and give up on the diet completely. Furthermore, you can help yourself through the transition period of low energy by planning your meals and meal prepping. It's recommended eating foods rich in potassium, magnesium, and sodium, as well as hydrating to ease keto flu symptoms. There are also electrolyte rehydration drinks that can help you replenish sodium, magnesium, and potassium levels. Drinking fluid and getting in these electrolytes can help ease some, but not all these symptoms, according to a book on the ketogenic diet published by StatPearls.
4. Forgetting to Eat Foods Rich in Omega-3 Fatty Acids
While fat reigns supreme on the diet, don’t just turn to bacon, cheese, and cream. There are both good and bad fats on keto! When choosing yours, aim to include healthy sources such as more anti-inflammatory omega-3s, particularly EPA and DHA, the type of fat found in salmon, sardines, oysters, herring, and mussels. (If seafood isn’t your thing, you can also take cod liver oil or krill oil, according to the National Institutes of Health Office of Dietary Supplements.) Other healthy fats are a good choice, too; if you haven’t stocked up on avocado, olive oil, and seeds such as chia seeds and flaxseed, definitely do. They’re not only keto friendly - they offer healthy polyunsaturated and monounsaturated fats that are heart protective, according to the American Heart Association.
5. Not Salting Your Food Enough
With people consuming more sodium than ever in a diet rich in processed food, you’re probably not used to hearing the call to eat more salt. But on keto, it’s necessary. As ketones build up in the body, they are excreted from the body through urine, which takes water and sodium out with it. In addition, you may be getting much less table salt (which is composed of 40 percent sodium and 60 percent chloride, per the Centers for Disease Control and Prevention [CDC]) now that you’ve kicked out the top source of salt in the standard American diet: packaged, processed foods, including bread, chips, crackers, and snack mixes, per the CDC. (There are a host of packaged keto foods now; though they should not play a large role in your diet, they can help you stay on track with your macro counts in a convenient way. If you’re eating these, check the sodium content on the label.) Chances are if you’re following a ketogenic diet you may need to prepare most, if not all, of your own meals and snacks from scratch, so simply season with salt.
6. Going It Alone and Not Clearing the Diet With Your Doctor
Many followers of the keto diet try it because they’re hoping to use it therapeutically for a medical condition. If that’s you, talk to your doctor first and make sure they’re on board with your plan - especially if you’re also taking medication. Some medications may need to be adjusted by your healthcare practitioner as your signs and symptoms improve. Just one example is insulin, as a lower dose may be needed now that you’re severely limiting carbohydrates.
7. Not Paying Attention to Your Veggie Intake
Vegetables have carbohydrates. And that means that you have to watch how much of them you eat - even lettuce. If you're not careful or are eating them as a free-for-all, you could overconsume carbs and kick yourself out of ketosis. On the other hand, you may be skipping veggies altogether if counting every baby carrot is getting too complicated. But it’s important to get your vegetables in (they contain the fiber that will prevent constipation, a potential side effect of keto, according to University of Chicago Medicine) while minding portions and properly counting carbs. Go for nonstarchy options in a rainbow of colors for a variety of nutrients, like leafy greens, cucumber, tomato, broccoli, cauliflower, bell peppers, and asparagus.
8. Getting Caught Up in Carb-Counting and Forgetting That Food Quality Matters
When it seems as if the sole goal of keto is to drastically cut carbs, the rest can feel like an afterthought. Reducing your carbohydrate intake is great, but higher-quality products, when your budget allows, will help improve your health, too. That means choosing omega 3-rich foods, like wild salmon; grass-fed, local, or organic meats; and snacking on whole foods rather than processed keto-approved treats. It also means trying to follow a balanced diet as best you can by incorporating as many nutrient-rich fruits and veggies as you can. Many registered dietitians aren’t fans of keto because it can lead to nutrient deficiencies. You can avoid this by working with an RD yourself as you follow keto.
Tips for Starting a Keto Diet
If you’re new to the keto diet, here are a few easy tips to getting your diet plan started.
Decrease Carbs (But Eat More Veggies)
Eating a very low carb diet is important to achieving ketosis, but low carb does not mean no carb. With Atkins 20, net carbs are restricted to 20g or fewer per day for about two weeks to guarantee that ketosis is achieved. After this induction phase, you will gradually add small amounts of net carbs back into your diet while still burning fat. You can easily count the net carbs you are consuming with the Atkins® app or this guide.When limiting your carb intake on a keto diet to 20-40 net grams per day, it is important to eat plenty of foundation vegetables to ensure you’re getting all of your necessary vitamins and minerals, as well as fiber. Reach for nutrient-dense, non-starchy veggies like kale, broccoli, spinach, asparagus, mushrooms, and peppers. The combination of eating whole foods plus gradually adding net carbs as you maintain ketosis also helps prevent setbacks, hunger pangs, and cravings for processed foods. Swap in low carb ingredients to make your favorite meals. For example, use zucchini noodles to replace regular noodles in your favorite pasta dish!
Decrease Stress
High levels of the stress hormone cortisol can elevate your blood sugar levels and get in the way of your body’s ability to achieve ketosis. If your job or personal life is currently more stressful than usual, you may want to wait to start a keto diet. You can also help reduce stress by getting lots of sleep, exercising regularly, and trying relaxation techniques like meditation or yoga. Prioritize sleep by sticking to a set bedtime schedule, and aim for a consistent 7-9 hours of sleep every night.
Increase Healthy Fats
Low carb keto diets replace your reduction of carbs with an increase in fat, which typically accounts for at least 60% of your daily calories. Because we’ve been told for so long to avoid fat, most people under eat fat when trying a keto diet. It is important to choose healthy fats from high-quality plant and animal sources, such as olive oil, avocado oil, and coconut oil as well as cheese, eggs, nuts, and fish. If you find yourself getting hungry between meals, you may not be consuming enough healthy fats.
Increase Exercise
Regularly exercising while on the keto diet can also help you achieve ketosis and transition into a low carb, high fat lifestyle more quickly than you would otherwise. That’s because to achieve ketosis, your body needs to get rid of any glucose, and the more often you exercise, the quicker your body uses up its glycogen stores before turning to fat for energy. It’s not uncommon to feel a bit sluggish when starting a keto diet. Ease into any new workout regimen, and be sure to include plenty of low intensity exercises as you adapt to your new diet.
Increase Your Water Intake
Water is crucial to supporting your metabolism and regular body functions, and low carb diets like keto have a diuretic effect on the body. Not consuming enough water, especially during the induction phase, can lead to constipation, dizziness, and cravings. In addition to drinking enough water, make sure you’re getting all of your electrolytes by adding some broth to your diet or a little extra salt to your food. Stay well hydrated and drink a minimum of 6 to 8 glasses of water daily. Drink even more if you have upped your exercise or if it’s a hot day.
Maintain Your Protein Intake
A keto diet requires eating enough protein to supply the liver with amino acids to make new glucose for the cells and organs, such as your kidneys and your red blood cells, that can’t use ketones or fatty acids as fuel. Not consuming enough protein can lead to loss of muscle mass, while consuming an excessive amount can prevent ketosis. When following a keto diet such as Atkins 20, aim for 20-30% of your diet to be made up of protein.
Maintain Your Social Life!
Starting a keto diet doesn’t mean you have to eat every meal at home. Make smart choices when dining out by checking the menu ahead of time, asking the restaurant for nutrition information, sticking to meat and veggie options, and opting for a side salad instead of a starchy side like fries. Replace sugar-laden condiments like BBQ sauce and ketchup with yellow mustard, ranch dressing, hot sauce, or butter.