The Keto Diet: Busting the “Fat Makes You Fat” Myth The ketogenic (keto) diet is a high-fat, low-carb diet that continues to gain popularity as more people recognize its benefits for reaching health and fitness goals. You might be wondering, “What is the keto diet all about, and can it work for me?” All your questions are about to be answered. You can use this page as your comprehensive guide for everything you need to know about the ketogenic diet and how to get started today. What Is the Ketogenic (Keto) Diet? The purpose of the keto diet is to force your body into a fat-burning state — burning fats instead of carbohydrates for fuel. This diet includes high amounts of fat, adequate amounts of protein, and low levels of carbs. Through this breakdown of macronutrients, you’re able to change how your body uses energy. To fully understand the process, it’s important to grasp how your body uses energy in the first place. How to Switch From Burning Carbs to Burning Fat When you eat a diet rich in carbohydrates, your body converts those carbs into glucose. This causes an insulin spike, as insulin carries the glucose to your bloodstream for energy. Glucose is your body’s preferred energy source. When glucose is present, your body will burn it before burning fat. A keto diet lowers your carb intake. A low-carbohydrate diet keeps your glucose levels lower, so your body can’t convert it to energy. This sends your body into a state known as ketosis, the basis of a ketogenic diet. Ketosis transforms your body into a fat-burning machine, burning fat (not carbs) for fuel. Specifically, the liver converts fatty acids in your body into ketone bodies, or ketones. This becomes your body’s new source of energy. When you transition to this high-fat diet, your body responds by becoming keto adaptive (aka fat adapted), which means it’s more efficient at burning fat[*]. Ketosis is a natural survival function of the body. It helps your body function on fat when food is not readily available. Similarly, the keto diet focuses on “starving” the body of carbohydrates, transforming the body into a fat-burning state and supplementing with optimal nutrition. Isn’t Fat Bad? The Truth About the “Fat Makes You Fat” Myth Nutritionists from the 1970s warned that saturated fats are bad, causing the United States to enter the era of low-fat eating. During this time, obesity in America soared while consumption of fat (particularly saturated fats) plummeted. Low-fat diet products became the norm at grocery stores as a high-carb, low-fat diet became the preferred method for weight loss. Yet people kept gaining weight. Clearly, something was not adding up. Today, new studies show that fats are not the real culprit[*]. A ketogenic diet dispels the “fat makes you fat” philosophy. First, a diet high in carbs (especially refined and processed carbs from low-fat diet products) can increase insulin and blood sugar levels and promote inflammation in the body. In contrast, a low-carb diet can help reduce inflammation far better than a low-fat diet[*]. Secondly, saturated fat is not shown to be harmful within the context of a low-carb diet. It helps improve cholesterol levels, including increasing the amount of HDL (good) cholesterol while decreasing total triglyceride levels. These two factors help lower your risk of heart disease[*][*]. Different Types of Ketogenic Diets There are four main types of ketogenic diets. Each one takes a slightly different approach to fat vs. carb intake. When deciding which method works best for you, take into account your goals, fitness level, and lifestyle. Standard Ketogenic Diet (SKD) This is the most common and recommended version of the keto diet. Here, you stay within 20-50 grams of net carbs per day, focusing on adequate protein intake and high-fat intake. Targeted Ketogenic Diet (TKD) If you are an active person, this approach might work best for you. Targeted keto involves eating roughly 25-50 grams of net carbs or less 30 minutes to an hour before exercise. Cyclical Ketogenic Diet (CKD) If keto seems intimidating to you, this is an excellent method to start off with. Here, you cycle between periods of eating a low-carb diet for several days, followed by a period of eating high-carb (typically lasting several days). High-Protein Keto Diet This approach is very similar to the standard (SKD) approach. The primary difference is the protein intake. Here you up your protein intake considerably. This version of the keto diet is more similar to the Atkins diet plan than the others. Note: The SKD method is the most used and researched version of keto. Therefore, the majority of the information below pertains to this standard method. How Much Protein, Fat, and Carbs Should You Eat on Keto? Fat, protein, and carbs are known as macronutrients. When you think of how to build a plate on keto (what each meal will look like), keep this breakdown in mind: High-fat Adequate protein Very low-carb Macronutrient Breakdown on Keto Calories from carbs: 5-10% Calories from protein: 20-25% Calories from fat: 75-80% (sometimes more for certain people) This is a general range, although numbers can vary slightly depending on each person’s needs and goals on the diet. For example, say someone requires 2,000 calories per day and is eating 75% fat, 20% protein, and 5% carbs. That would come out to 1,500 calories/167 grams of fat, 400 calories/100 grams of protein, and 100 calories/25 grams of carbs. This person would need to make sure they stay at or below 25 grams of carbs each day if they want to lose weight. Carb Intake For most people, a range of 20-50 grams of carbohydrate intake per day is ideal. Some individuals can go as high as 100 grams per day and stay in ketosis. Protein Intake To determine how much protein to consume, take into account your body composition, ideal weight, gender, height, and activity level. Ideally, you should consume 0.8 grams of protein per pound of lean body mass. This will prevent muscle loss. And don’t worry about eating “too much” protein keto — it won’t kick you out ketosis. Check out the video below by Perfect Keto founder Dr. Anthony Gustin to understand the role protein plays in keto and why gluconeogenesis is not a problem: Fat Intake After you calculate the percentage of daily calories that should come from protein and carbs, total the two numbers, and subtract from 100. That number is the percent of calories that should come from fat. Calorie counting is not required on keto, nor should it be necessary. When you eat a diet high in fat, it’s more satiating than a diet high in carbs and sugar. Generally, this cuts down on your chances of overeating. Instead of counting calories, pay attention to your macro levels. For further reading, learn more about micronutrients on a keto diet. What’s the Difference Between Keto and Low-Carb? The keto diet often gets lumped in with other low-carb diets. However, the main difference between keto and low-carb is the macronutrient levels. In most keto variations, 45% of your calories or more will come from fat, to help transition your body into ketosis. In a low-carb diet, there’s no specified daily intake of fat (or other macronutrients). The goals between these diets also vary. The goal of keto is to enter ketosis, weaning your body off of burning glucose for fuel long-term. With a low-carb diet, you may never enter ketosis. In fact, some diets cut out carbs in the short-term, then add them back in. Foods to Eat on the Keto Diet The following is a list of foods that you can eat on the keto diet. This isn’t a completely comprehensive list, but it should give a good idea of where to start to make the most of this diet plan. Meat, Eggs, and Nuts All meat and seafood are included on the keto diet, as long as it’s not breaded or fried. Enjoy beef, chicken, pork, lamb, goat, turkey, and veal. You can also enjoy fatty fish like salmon, tuna, trout, and sardines. Always choose the highest quality meat you can afford, whether that means grass-fed or organic. Eggs are always a great choice, preferably free-range. Nuts and seeds are also fine, including almonds, pecans, chia seeds, and flax seeds. Low-Carb Vegetables On a keto meal plan, feel free to fill your plate with low-carb vegetables — particularly leafy greens. It’s a great way to get a healthy dose of micronutrients, thus preventing vitamin deficiencies on keto. Options like kale, broccoli, cauliflower, Brussels sprouts, asparagus, peppers, spinach, and onions are all great options. Keto-Friendly Dairy If you can tolerate dairy, it is allowed on the keto diet. Always choose keto-friendly dairy options, which are organic and grass-fed whenever possible. Select full-fat dairy at the grocery store, such as cheese, sour cream, yogurt, and heavy cream. Low-Sugar Fruits Although you must approach fruit with caution on keto, if you are craving something light and sweet, include berries — such as blueberries or raspberries — in moderation. There is one fruit you can consume abundantly on keto: avocados. Healthy Fats and Oils Both animal fats (saturated fats) and plant-based fats can be consumed on the keto diet. Healthy fat sources include butter, tallow, and ghee from animals or coconut oil, olive oil, sustainable palm oil, and MCT oil from plants. Herbs and Spices Use seasonings freely on keto — just make sure they don’t have any added sugar or starchy separators. Wondering how to integrate all of these foods into your daily meals? Check out the full library of keto recipes. Foods to Avoid on Keto While there are numerous foods you can enjoy on a keto diet, there are certain foods you’ll want to avoid so you can reap the full benefits of achieving ketosis. Grains Grains are loaded with carbs, so it’s best to avoid all grains on keto. Whole grains, wheat, pasta, rice, oats, barley, rye, corn, and quinoa are all out. Instead, try these low-carb substitutes. Beans and Legumes While many vegetarians eat beans for their protein content, they are actually incredibly high-carb. Avoid eating kidney beans, chickpeas, black beans, and lentils. Higher-Sugar Fruits While fruit offers many nutrients, they’re not keto-friendly due to copious amounts of sugar. Avoid apples, mangoes, pineapple and other fruits (with the exception of berries in small quantities). Starch Avoid starchy vegetables like potatoes, sweet potatoes, certain squash, parsnips, and carrots. Like fruit, there are health benefits to these foods. However, you can find those vitamins and minerals from more low-carb sources — ones that won’t kick you out of ketosis. Sugar-Laden Products This includes, but is not limited to, desserts, artificial sweeteners, smoothies, soda, and fruit juice. Even condiments are usually filled with sugar, so put down the ketchup and mayo. If you are craving a dessert, try one of these keto-friendly dessert recipes instead. Alcohol Yes, alcohol is sugar. So set down that glass of wine. If you’re at a social event, follow these handy guidelines for low-carb alcohol. Seed Oils Seed oils, particularly when heated, are not a good idea. They contain large amounts of omega-6 fatty acids, which are inflammatory in large amounts. Learn more about the top vegetable and seed oils to avoid on keto. Health Benefits of a Keto Diet Since a low-carb diet has been shown to have greater effects on weight loss than other diets, it’s a good option when you want to lose weight and lower your blood pressure and cholesterol. Plus, a ketogenic diet may also help improve insulin resistance and lower glucose levels. Using Keto to Treat Disease In various studies, researchers have shown that keto can help with the following: Eliminating diseases related to blood sugar like type 2 diabetes[*] Reducing risk factors for heart disease, including improvement in HDL cholesterol, triglycerides, and LDL cholesterol (related to plaque in the arteries)[*] Decreasing skin inflammation and lesions in those with acne[*] Preventing seizures in people, especially children, with epilepsy[*] Slower tumor growth with patients diagnosed with prostate, pancreatic, brain, lung and gastric cancer[*] Using Keto to Improve Endurance Levels The ketogenic diet may help improve endurance levels for athletes. However, it may take time for athletes to adjust to burning fat instead of glucose. Studies show that aerobic endurance is not decreased with a ketogenic diet[*]. However, athletes who switch to keto might experience limitations in performance at the beginning. This is simply the body adjusting to using fat as its preferred energy source. Using Keto to Improve Metabolic Functions Studies show multiple long-term benefits of a keto diet on a person’s weight and health. It significantly decreased body weight, body fat, and body mass in various studies[*]. Keto has also been shown to kick your body into a high-performing metabolic state, increasing fat metabolism during exercise[*]. As long as you continue to consume 1-1.2 grams of protein per pound of body mass, you can preserve muscle mass while still burning fat. How to Know When You’re In Ketosis Ketosis can be a gray area, as there are varying degrees of it. In general, it can often take around 1-3 days to reach full ketosis. The best way to monitor your ketone levels is through testing, which you can do from home. When you eat a ketogenic diet, excess ketones spill over into several areas of the body. This allows you to measure your ketone levels in various ways: In your urine with a test strip In your blood with a glucose meter On your breath with a breath meter Each method has its advantages and disadvantages, but measuring ketones in your blood is often the most effective. Although it’s the most affordable, urine testing is typically the least accurate method. Possible Concerns With the Keto Diet When implementing any new diet — not just keto — it’s important to do so safely, and in a way that supports your unique lifestyle. With this in mind, here are two potential side effects you should know about: Ketoacidosis Those with diabetes should be aware of diabetic ketoacidosis. This is a rare but dangerous state for diabetics who don’t make enough insulin, get sick or hurt or aren’t drinking enough fluids. Other causes of ketoacidosis could include alcoholism, an overactive thyroid, or true starvation. In ketoacidosis, ketones levels reach an extremely high level, causing the blood to become acidic. For more information, read the complete guide on ketosis vs. ketoacidosis. Keto Flu Within the first two weeks of starting keto, some people may experience adverse effects known as “keto flu.” This results from the sudden removal of carbohydrates from the brain and body. These are minor but uncomfortable symptoms that might include: Mental fogginess Headaches Nausea Weakness Constipation Dizziness If you experience keto flu, drink plenty of water. Increasing your salt intake can also help minimize symptoms. Another option is to lower your carb intake gradually. This will extend the amount of time it takes to get you into ketosis but will make for a much more pleasant experience. It’s Time to Begin Your Keto Journey Now that you have a better idea about what the keto diet is all about, it’s time to take that first step in improving your health. Check out this guide on keto for beginners to discover how you can embark on this exciting and healthy lifestyle.