The ketogenic diet, often shortened to "keto," is a dietary approach characterized by a very low intake of carbohydrates and a high consumption of fats. This dietary shift prompts the body to enter a metabolic state called ketosis, where it begins to utilize fat as its primary energy source instead of carbohydrates. This article serves as a comprehensive guide for beginners looking to understand and implement the keto diet effectively.
Keto Basics
The ketogenic diet shares similarities with the Atkins and other low-carb diets. It involves a drastic reduction in carbohydrate intake, 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 (6). Ketogenic diets can cause significant reductions in blood sugar and insulin levels. This, along with the increased ketones, has some health benefits (6, 7, 8).
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 (6).
Protein intake should also be moderate. This is because protein can be converted into glucose if consumed in high amounts, which may slow your transition into ketosis (10). 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 (11).
Blood, urine, and breath tests are available, which can help determine whether you’ve entered ketosis by measuring the amount 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 (12).
Read also: Easy Low-Carb Cheese Crackers
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 (9).
- 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.
Health Benefits of the Keto Diet
A ketogenic diet is an effective way to lose weight and lower risk factors for disease (1, 2, 3, 4, 5). In fact, research shows that the ketogenic diet may be as effective for weight loss as a low fat diet (13, 14, 15). What’s more, the diet is so filling that you can lose weight without counting calories or tracking your food intake (16).
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 (13). 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 (17). The increased ketones, lower blood sugar levels, and improved insulin sensitivity may also play a key role (18, 19).
Keto and Diabetes
Diabetes is characterized by changes in metabolism, high blood sugar, and impaired insulin function (20). One older study found that the ketogenic diet improved insulin sensitivity by a whopping 75% (25). 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 (26). 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. This is an important benefit when considering the link between weight and type 2 diabetes (24, 27). 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 (27). The ketogenic diet can boost insulin sensitivity and cause fat loss, leading to significant health benefits for people with type 2 diabetes or prediabetes.
Read also: Keto Calorie Counting: A Detailed Guide
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 (28, 29).
- Cancer: The diet is currently being explored as an additional treatment for cancer, because it may help slow tumor growth. (4, 30, 31).
- Alzheimer’s disease: The keto diet may help reduce symptoms of Alzheimer’s disease and slow its progression (5, 32, 33).
- Epilepsy: Research has shown that the ketogenic diet can cause significant reductions in seizures in epileptic children (3).
- Parkinson’s disease: Although more research is needed, one study found that the diet helped improve symptoms of Parkinson’s disease (34).
- Polycystic ovary syndrome: The ketogenic diet can help reduce insulin levels, which may play a key role in polycystic ovary syndrome (35, 36).
- Brain injuries: Some research suggests that the diet could improve outcomes of traumatic brain injuries (37).
However, keep in mind that research into many of these areas is far from conclusive. A ketogenic diet may provide many health benefits, especially with metabolic, neurological, or insulin-related diseases.
Foods to Avoid and Embrace on Keto
Navigating the keto diet requires understanding which foods to limit or avoid entirely, and which to embrace as dietary staples.
Foods to Avoid
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.
Avoid carb-based foods like grains, sugars, legumes, rice, potatoes, candy, juice, and even most fruits.
Read also: Magnesium Supplements for Keto
Foods to Embrace
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. Base the majority of your diet on foods such as meat, fish, eggs, butter, nuts, healthy oils, avocados, and plenty of low carb veggies.
Sample Keto Meal Plan
Here is a sample ketogenic diet meal plan for one 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 (more keto smoothies here) 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 and mushroomslunch: 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. You can eat a wide variety of tasty and nutritious meals on a ketogenic diet. It’s not all meats and fats. Order this and replace any high carb food with extra vegetables. Egg-based meals are also a great option, such as an omelet or eggs and bacon. Another favorite is bun-less burgers. You could also swap the fries for vegetables instead. Add extra avocado, cheese, bacon, or eggs. 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.
When eating out, select a meat-, fish-, or egg-based dish. Order extra veggies instead of carbs or starches, and have cheese for dessert.
Potential 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 (38). 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 (39). Other less common symptoms include:
- Poor energy and mental function
- Increased hunger
- Sleep issues
- Nausea
- Digestive discomfort
- 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. Many of the side effects of starting a ketogenic diet can be limited. Easing into the diet and taking mineral supplements can help.
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 (40, 41). 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. There are some side effects to the keto diet about which you should speak to your doctor if you plan to stay on the diet long term.
Helpful Supplements for Keto
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. Shop for MCT oil online (42, 43). Mix a scoop with your favorite beverage for an easy, satisfying treat.
- Minerals: Added salt and other minerals can be important when starting out due to shifts in water and mineral balance (44). When in ketosis, your body naturally flushes more fluids, which can cause unwanted side effects such as muscle cramps, fatigue and headaches.
- Caffeine: Caffeine can have benefits for energy, fat loss, and performance (45).
- Exogenous ketones: This supplement may help raise the body’s ketone levels (46).
- Creatine: Creatine provides numerous benefits for health and performance. This can help if you are combining a ketogenic diet with exercise (47).
- Whey: Use half a scoop of whey protein in shakes or yogurt to increase your daily protein intake (48, 49). Shop for tasty whey products on online.
Certain supplements can be beneficial on a ketogenic diet. These include exogenous ketones, MCT oil, and minerals. Perfect Keto is a brand that offers supplements designed to support a ketogenic lifestyle. Keto Bars are packed full of quality ingredients that provide sustained energy to fuel your mind and body. "Perfect Keto is my favorite because there are never any artificial or scary ingredients." "I add Perfect Keto to my coffee, smoothies, and even use them to make keto-friendly protein bars." "Perfect Keto makes it easy to stay keto, have high energy, and get shit done." "Perfect Keto is the cleanest out here."
Common Questions About the Keto Diet
Here are answers to some of the most common questions about the ketogenic diet.
Can I ever eat carbs again?
- Yes. However, it’s important to significantly reduce your carb intake initially. After the first 2 to 3 months, you can eat carbs on special occasions - just return to the diet immediately after.
Will I lose muscle?
- There’s a risk of losing some muscle on any diet. However, protein intake and high ketone levels may help minimize muscle loss, especially if you lift weights (50, 51).
Can I build muscle on a ketogenic diet?
- Yes, but it may not work as well as on a moderate carb diet (52, 53).