Meaning of Low-Carb High-Fat Diet — From Ketogenic Principles to Ketosis and Carbohydrate Restriction Standards
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"Doctor, is it really possible to lose weight while eating meat freely?"
This is a question I hear very often when doing diet consultations in the clinic. Many people think that if you eat a lot of fat, you will naturally gain weight. But the diet that has become popular in recent years has completely overturned that common sense. Today, I will calmly go over the meaning of the low-carb high-fat diet that many of you are curious about and the principles hidden within it.
What exactly is the low-carb high-fat diet
Low-carb high-fat is simply an abbreviation for Low Carbohydrate High Fat, LCHF diet. It refers to a dietary therapy that drastically reduces carbohydrate intake from staple foods like rice, bread, and noodles that we normally eat, and fills that void with healthy fats.
![Flow chart showing the energy source switching process. [Reduced carbohydrate intake] → [Fat breakdown in liver] → [Ketone production] → [Using fat as energy] with arrows connecting each step]](/api/files/assets/2026-08/86f9bb73.jpg?sig=5a82c73138d3ef05b70fe6db96405b747317c180f2b9b93159767b3d2170092e)
In English, it's commonly called Ketogenic or Keto diet. The core of this diet is to change the way our body obtains energy. Normally, the human body uses sugar (glucose) obtained from grains or fruits as its 1st priority energy source. However, when carbohydrate supply is cut off, the liver breaks down fat to produce a substance called "ketone," which becomes the main energy source.
Background and origins of the sudden popularity
Many people think this diet is simply a recent trend, but its roots actually run very deep. The low-carb high-fat dietary therapy was originally created in the 1920s as a medical diet for treating pediatric epilepsy patients and brain tumor patients.
Then in 2014, American journalist Nina Teicholz widely publicized the weight loss effects of this method to the general public, sparking a global craze. The treatment method transitioned into the realm of diet, creating the current "keto craze."
Key rules for successful implementation
To properly follow the low-carb high-fat diet, you need to do more than simply eat less rice; you need to precisely adjust the ratio of nutrients. I'll organize the guidelines I provide to patients in the clinic.
![Diet practice checklist. The left side shows ✅ recommended foods (meat, fish, eggs, cheese), and the right side shows ✗ restricted foods (sugar, bread, pasta, rice), arranged in comparison with icons]](/api/files/assets/2026-08/109f91a1.jpg?sig=b79490db4f0ba221ecf1a405d88a36be24274cd0588322740038bd67617d7577)
Nutrient Intake Ratio: Generally, a method is used to limit carbohydrates to 10% or less of total calories, proteins to around 20%, and fill the remaining 70% with fats. However, the American Academy of Family Physicians also views consuming less than 20% of total intake calories as carbohydrates as the definition.
Recommended Foods: Eat foods high in fat and protein, such as meat, poultry, fish, shellfish, eggs, cheese, nuts, and seeds.
Restricted Foods: Foods high in carbohydrates, such as sugar, bread, pasta, and rice, should be avoided.
Essential Elements: Intake of fiber-rich vegetables and sufficient hydration are essential. Salad vegetables such as spinach, kale, and Swiss chard are low in carbohydrates, so you may eat them freely.
Common Misconceptions and Precautions
The most common misconception is thinking, "I just need to eat a lot of pork belly." However, the essence of LCHF (Low Carb High Fat) is not simply eating a lot of fat, but making the metabolism reach a state of Ketosis.
Ketosis refers to a state where the body uses fat as its primary fuel instead of glucose. Until entering this state, lethargy or headaches, so-called 'Keto Flu,' may occur. Looking at patient cases between consultations, there are quite a few instances where people give up because they cannot endure this process in the beginning. It is important to give your body time to adapt rather than blindly increasing fat.
Actual Effects from a Diet Perspective
Is this diet really effective? To give the conclusion first, the initial weight loss speed is very fast. However, there is a slight trick here. When carbohydrate intake is reduced, water leaves the body quickly along with glycogen, which causes the numbers to drop sharply in the beginning.
Compared to general recommended diets, the difference becomes even clearer. General macronutrient intake guides recommend carbohydrates at 45~65% of total calories, and the Korean Diabetes Association 2015 guidelines also recommend 50~60%. Compared to this, low-carb high-fat is quite an extreme restricted diet.
If you want effective weight loss, choose 'good fats' instead of 'bad fats.' For example, 1 tablespoon of olive oil contains about 13.5g of fat, of which saturated fat is only 2g. We recommend utilizing healthy fat sources like half an avocado (protein 1.3g, fat 10g) or 1 tablespoon of almond butter (98kcal).
For Sustainable Dieting
Low-carb high-fat can certainly be a powerful tool, but it's not an easy method for everyone to follow. Since nutrient intake is overly restricted, it's difficult to maintain long-term, and some people may find it doesn't suit their body type.
What's important is to accurately understand your body's condition and lose weight at an appropriate pace for you. If you've experienced loss of energy or metabolic breakdown due to excessive dietary restrictions, you need a process of adjustment tailored to your body type with professional help.
With the Baekrok Gambi-jung program, you can reduce the difficulties that come with dietary adjustments and expect more effective results. Based on today's content, try the diet and please be sure to let us know how your body responded at your next visit.
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