Eat Fat to Burn Fat? Here’s What You Need to Know About a Ketogenic Diet
The ketogenic diet (or “keto” diet) is an eating style that is very high in fats and very low in carbs. Many people say—and some studies show—that it can help to lose weight. It’s by no means a magic weight loss diet that works all of the time, is easy to stick to, and contains all of the nutrition you need. The keto diet is something that you may consider, but not until after you read my latest post about it.
“Going keto” actually changes your metabolism, so it may or may not be right for you. This depends on your personal medical history and health goals. There are many conditions where the diet is not recommended, and even a few where it is most definitely recommended.
You may have heard of the ketogenic diet or keto diet for short. It’s a 100-year-old diet whose popularity has risen lately, in part due to celebrities who say the keto diet has helped them to lose weight. It’s also endorsed by some endurance athletes like marathon runners and triathletes. Studies confirm that the keto diet can help some people lose weight (at least in the short term).
The keto diet is a low-carbohydrate high-fat eating style that influences your body to burn fat as “fuel.” It works by changing your metabolism from using carbohydrates as your body’s preferred fuel to using fat (and ketones) instead. This metabolic change allows your body to maintain energy levels while consuming fewer calories, hence the weight loss.
How can you change your metabolism like that? Who should and shouldn’t try the keto diet? What foods are ketogenic-friendly? Read on to find out.
Food as fuel: carbohydrates vs. fats (and ketones)
Your body and brain prefer using carbohydrates, or carbs, as their main fuel source. Carbs are mostly sugars and starches that are found in many foods such as grains, legumes, fruits, and vegetables. Humans have evolved the ability to use a backup fuel to survive during times when we don’t have enough carbohydrate-rich foods to eat. Our survival in times of starvation depends on our body’s ability to fuel our brains, heart, muscles, and other critical organs we need to stay alive. So, what does your body do when there aren’t enough carbs to use? It turns to your backup fuel: fat.
It may sound counterintuitive, but the ketogenic diet mimics the effects of fasting without actually fasting. This happens by reducing the amount of carbs you consume so your body adapts and starts using fat. When this happens, our bodies naturally produce a type of biochemical called ketones. The word ketogenic means that our body is generating ketones and this can continue for as long as you eat a ketogenic diet.
Benefits and risks of “going keto”
The keto diet is not for everyone because it can be very restrictive and requires a lot of measuring of your macronutrient intake (fats, carbs, and proteins). A small number of people have metabolic reasons why it’s medically recommended that they do eat a ketogenic diet (e.g., they have glucose transporter 1 deficiency syndrome or pyruvate dehydrogenase deficiency). Other people with drug-resistant epilepsy may also be recommended a ketogenic diet because it can help reduce the number of seizures (although this has mainly been studied in children, not adults). In fact, the seizure-reducing ability of the keto diet was first studied in 1921, and was a common treatment until the advent of anti-epileptic medications. People on a keto diet—especially children—need to be closely monitored to ensure they’re getting enough nutrition because there are so many foods that they cannot eat.
As mentioned above, there are a few medical reasons why some people should eat a ketogenic diet. However, there are many conditions that do not mix well with the keto diet, as it can make things worse. If you have any of these metabolic conditions, don’t try a ketogenic diet without consulting a healthcare professional first:
Primary carnitine deficiency
Carnitine palmitoyltransferase deficiency
Carnitine translocase deficiency
Pyruvate carboxylase deficiency
Acyl dehydrogenase deficiency
Long- or medium-chain 3-hydroxyacyl-coenzyme A deficiency
Most people don’t fall into the above-mentioned categories where a ketogenic diet is medically recommended, or not recommended. For everyone else, the diet comes with a list of potential side effects. The most common one affects between 14 and 46 percent of people, and it’s constipation.
Other side effects of a keto diet can include:
Nutrient deficiencies (e.g., failure for children to grow, low bone density)
Lethargy, “fuzzy thinking,” and mood swings
Metabolic issues (e.g., dehydration, hypoglycemia, excessive ketosis, metabolic acidosis, and electrolyte imbalance)
Digestive issues (e.g., constipation, nausea, vomiting)
Liver, pancreas, and kidney issues (e.g., hepatitis, pancreatitis, kidney stones)
Heart and blood fat issues (e.g., cholesterol)
It can take two or three weeks of eating a strict keto diet before your body fully adapts to ketosis and uses fat for fuel. During this transition time, you may experience something referred to as the “keto flu.” It’s not an official term, nor is it related to an influenza infection. The keto flu can feel like a headache, fatigue, nausea, sleep difficulties, and constipation.
As you can see, there are many reasons to consult a knowledgeable healthcare professional before starting a ketogenic diet. It’s also a good idea to periodically be monitored as long as you’re eating that way.
If keto is right for you, here is how to get into ketosis
There are a few different low-carb high-fat ways to get your body into ketosis. The first is with the classic ketogenic diet, and there are three modifications that can also work. As you’ll see below, there is very special attention paid to the exact amounts of fats and carbohydrates to eat each day to achieve and maintain ketosis on these diets.
1 - The classic ketogenic diet
The classic keto diet requires about 90 percent of your calorie intake to be fat and 4 percent carbohydrates. This leaves just 6 percent for proteins. Many very healthy and nutrient-dense foods contain more than 5 or 10 percent carbohydrates (think: vegetables). And if you don’t eat a lot of vegetables, you can become deficient in many nutrients. That’s why this diet often comes with a recommendation to take vitamin and mineral supplements.
Also, because the level of carbohydrates needs to be so low, even the tiny amount of carbohydrates you may be taking in supplements and medications need to be monitored.
2 - Three modified ketogenic diets
There are three modifications to the classic ketogenic diet that can maintain the state of ketosis without eating 90 percent of your calories as fat.
The first is the medium-chain triglyceride diet (MCTD). This modification allows 73 percent of calories from fat and 17 percent carbohydrates (and 10 percent protein). However, you have to include a specific kind of fat called a medium-chain triglyceride, or MCT. The MCTD recommends that MCTs make up about half of the fats ingested. This means that if you don’t use concentrated MCT oil as part of your keto diet, coconut oil would be your main daily fat source because, unlike other fats like olive oil, it contains MCTs.
The second modification to the ketogenic diet is called the Modified Atkins Diet (MAD). This reduces the fat intake to 65 percent of calories from fat as long as the carbohydrate intake stays below 5 percent of calories. This means that the remaining 30 percent can be protein.
The third modification is the Low Glycemic Index Diet (LGID). This one targets 60 percent of the calories from fat, 10 percent from carbohydrates, and 30 percent from protein. Because it allows a higher intake of carbohydrates, the carbohydrates eaten must be low glycemic (which means they have little impact on your blood sugar).
What does the keto diet look like from a food and meal perspective?
Foods to eat and avoid for a ketogenic diet
Depending on how strict your keto diet is (90, 73, 65, or 60 percent fat) you need to measure your intake of fats and carbohydrates. Here is a list of some of the higher-fat, lower-carbohydrate foods that can often be incorporated into a keto diet:
Berries (in small amounts)
Leafy greens (kale, spinach, Swiss chard)
Broccoli, cauliflower, Brussels sprouts
Onions and garlic
Full-fat dairy (cheese, plain Greek yogurt)
Nuts (almonds, walnuts)
Oils (olive, coconut, palm)
Fats (lard, butter, cocoa butter)
Drink plain or sparkling water, and unsweetened coffee or tea
Here is a list of foods to avoid on a keto diet:
Breads and baked goods
Starchy vegetables (potatoes, corn, peas, beans)
Fruit (except berries)
The most important thing is to ensure that any diet you eat—whether it’s keto or otherwise—is nutritionally balanced and provides you with enough of all of the essential nutrients you need every day.
The keto diet is very popular now and it may (or may not) be for you. More research is needed to know if the keto diet can help people lose weight and keep it off.
The keto diet is recommended for a few people, but not recommended for everyone. Because it is restrictive, it can result in nutrient deficiencies, metabolic issues, digestive symptoms, as well as blood lipid concerns, to name a few.
There are several ways to get into the state of ketosis and start burning fat as fuel. One is with the classic keto diet, or one of three modifications that can also work. Whichever method you go with, it’s going to require a lot of measuring of the fats and carbs in the foods you eat, and might feel very restrictive.
To know if the keto diet may work for you, consult a certified dietitian who can review your health goals and nutritional status. Here is my link to book a chat about making sure to meet your dietary needs.
Heard some amazing stories about keto and want to know if it’s right for you? What are the best macros to eat to reach ketosis? Need a personalized list of recipes and a meal plan to help you enjoy food and reach your health goals? Book an appointment with me to see if my product/program/service can help you. Click here to schedule your free consultation.
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