A Practical, Easy-to-Apply Three-in-One Vegetarian Method

Husband "Honey — why am I so tired? I just ate, and I have no energy…"

Wife "It's because all you eat is rice. We must be missing something!"

Wife "Honey, look at this! It's the Three-in-One Vegetarian Method! Grains + beans·nuts + vegetables·fruits·sea vegetables!"

Husband (eyes lighting up) "Three-in-One?! Bean rice, nuts, tofu and seasoned greens… I think I can do this!"

Husband "Honey, what about pecans, walnuts, and almonds — does that count as Three-in-One?"

Wife "Of course~! They're packed with rich, nutty fats and protein!"

Husband "Wow! Lately my body feels lighter from the moment I wake up. Three-in-One is amazing!"

Wife (smiling) "The Three-in-One Method has saved us as a couple. Now both body and mind are in harmony!"

A Practical, Easy-to-Apply Three-in-One Vegetarian Method

Zoe "Doctor, since the last class I've become really interested in the ketogenic diet. So during the break I searched online. As you said, the ketogenic diet seems to help with so many illnesses. But most of the ketogenic diets I found use pork lard, butter, and olive oil. I came to vegetarianism because of my dog, so unfortunately, it seems like a vegetarian like me wouldn't be able to follow a ketogenic diet."

Dr. Lee "Ha! So that's why you looked discouraged today. But don't give up. With plants alone, you can absolutely do a ketogenic diet — and even more deliciously and healthily. That's exactly why this course is called the Plant-Based Ketogenic Diet. Once everyone arrives, I'll explain in detail."

Zoe's eyes widened, and she smiled with relief.

Zoe "Really? Then I can do it too?"

About five minutes later, the others all arrived.

Dr. Lee "Thank you all for coming early again this morning. Grace, you live in Uijeongbu — isn't it hard to come all the way here at your age?"

Grace "No, Doctor, I'm fine. To be honest, I really enjoy coming to this class. I worked as a hospital dietitian in the U.S. for over thirty years, but there are so many things I'm learning here that surprise me. My son graduated from Johns Hopkins Medical School and works as a doctor in the U.S. He's a wonderful and intelligent son, but he doesn't follow a vegetarian diet. As someone who has been vegetarian my entire life, I've always wished he would too. So, Doctor, if you ever publish The Healing Science of Vegetarianism in English, I'd love to give a copy to my son."

Dr. Lee "Of course. It will probably take about a month. I'll have it bound in hardcover for you."

Grace "Thank you so much."

Dr. Lee "All right, today I'll show you how to do a ketogenic diet — fasting while still eating — using only plant foods. To do this, it helps to first understand the Three-in-One Vegetarian Method."

Emily "The Three-in-One Method? Isn't 'Trinity' a Christian doctrine?"

Dr. Lee "Yes, that's right. In Christianity, the Trinity is the doctrine that the Father, Son, and Holy Spirit are one. In Buddhism there's a similar idea — the Three Bodies of the Buddha: Dharmakāya, Sambhogakāya, and Nirmanakāya. And in Hinduism there are three deities: Brahman, Ishvara, and Avatar. These seem to correspond to the Buddhist three bodies — Brahman is the universe itself, Ishvara is the personal god, and Avatar is the deity in human form. But the Three-in-One Vegetarian Method has nothing to do with religion. It simply means that when planning a meal, including three food groups together makes it easy to eat in a nutritionally balanced way."

The complex 5- or 6-food-group system is hard to apply in everyday life

Emily "I've learned that nutrition usually divides foods into 5 or 6 groups."

Dr. Lee "That's right. Modern nutrition divides foods into grains, meat·fish, vegetables, fats, dairy, and fruits. But applying this in everyday life is not easy. And making milk — a single food — into its own food group is a strange thing to do."

Emily "I learned that milk is its own group because it's rich in calcium."

Dr. Lee "Yes. But foods rich in calcium are actually found more abundantly in seeds. For example, black sesame seeds contain 200 times more calcium than beef. And when most people plan meals, calcium often comes out below the recommended intake. But that's actually to be expected. As I mentioned last time, the recommended intake is set based on the upper 97.5% of people who need the most. On average, you can take about 20 to 30% off the recommended intake — and even without milk, today's diets reach about 70% of the current recommended intake.

"Calcium is 10,000 to 100,000 times more concentrated in the blood than inside cells. So when calcium channels in the cell membrane open, various cellular functions are triggered. In brain cells too, calcium channels at nerve endings let calcium move into the cell, which then causes neurotransmitter-containing vesicles to fuse with the membrane and release neurotransmitters. So calcium is important — but too much also causes problems. Things like cataracts and kidney stones can occur. So if you eat enough calcium to meet the recommended intake, 97.5% of people will be in a state of excess. In other words, making milk into its own food group just to supply calcium is, frankly, a bit of a nonsense."

Table 2-1. Comparison of the 6-food-group system and the Three-in-One food groups.

6-food group	Foods	Main nutrients	Three-in-One group
Grains	Grains	Carbohydrates	Grains
Meat·fish	Fish, meat	Protein, lipid	Beans, nuts, seeds
Vegetables	Vegetables	Vitamins	Vegetables·fruits
Fats	Oils, butter, cheese	Fat	—
Dairy	Milk, dairy	Calcium, fat	—
Fruits	Fruits	Vitamins	—

Emily "So instead of 6 food groups, it would be 5 food groups?"

Dr. Lee "Right. And of those, the vegetable group and the fruit group can be combined into one. Fruits are expensive in Korea, so eating only vegetables is fine. In fact, vegetables have been reported to have stronger anti-cancer effects than fruits. And there's no need to make a separate 'fats' group either. The recommended intake for fat — that is, lipid — has never been scientifically fixed. Conventionally, nutrition has set lipid intake at 10% of total calories, sometimes 20%, and recently up to 30%. As scientific evidence accumulates, the recommended lipid proportion will likely keep rising.

"In conclusion, the dairy and fats groups can be eliminated, and the vegetable and fruit groups can be combined into 'vegetables·fruits.' This leaves three groups: grains, meat·fish, and vegetables·fruits. Since we use plant foods, I'll rename 'meat·fish' to 'protein·lipid.'"

Just three food groups are enough to plan a meal

Just three food groups are enough to plan a meal

Zoe "So when planning a vegetarian meal with these three groups — grains, protein·lipid, and vegetables·fruits — if I include one from each, I'll get balanced nutrition?"

 

Dr. Lee "Exactly. To understand why, it helps to know that each of the three food groups contains different main nutrients. First, let's look at grains. The representative grains are rice and wheat. Other grains include Job's tears, millet, barley, sorghum, and buckwheat. The main nutrient in these grains is carbohydrates. Looking at Table 2-2, rice is 78% carbohydrate. Protein is about 7 to 11%. Lipid, on the other hand, is only 1 to 2% — very low. The rest is water. So you can simply think of grains as 'lumps of carbohydrate.'"

 

Susan "Then what foods are in the protein·lipid group?"

 

Dr. Lee "The protein·lipid group includes foods rich in both protein and lipid — three subgroups: beans, nuts, and seeds. Common beans we eat daily include soybeans (used to make doenjang) and seoritae black soybeans. Nuts include walnuts, pecans, cashews, almonds, macadamia, Brazil nuts, and others. Seeds include pine nuts, perilla seeds, sesame seeds, and black sesame seeds. Nutritionally, these are about 30% protein and 40% lipid. Since beef — known as a high-protein food — is only about 20% protein, plant-based protein·lipid foods can actually be considered better in terms of protein content. They're also rich in insoluble fiber, which increases stool volume, healthily stimulates the intestinal wall, promotes intestinal motility — speeding up the passage of stool — and supports beneficial gut bacteria. Fiber is the food of beneficial gut microbes."

 

 

Table 2-2. Major nutrient ratios in the Three-in-One food groups.

Main nutrient	Group	Examples	Carb	Protein	Lipid
Carbohydrate	Whole grains	Brown rice, whole wheat, barley	70–75%	7–10%	1–2%
Protein + Lipid	Legumes	Mung bean, red bean, peas	20–50%	18–20%	20–30%
	Soybean	Soybean	18–20%	38–40%	15–17%
	Seeds	Perilla, sunflower seeds	18–20%	18–20%	40–50%
	Nuts	Walnut, pecan, almond	20–25%	15–18%	50–60%
Vitamins	Vegetables	Root, leafy	5–6%	2–5%	0.1–1%
	Fruits	Apple, pear, plum	10–15%	0.1–1%	0.1–1%

 

Figure 2-1. The Three-in-One Vegetarian Food Groups.

When designing a vegetarian meal, it is best to include three food groups: first, whole grains for fiber-rich carbohydrates; second, beans, nuts, and seeds for high-quality protein and lipid; and third, vegetables, sea vegetables, and fruits for water-soluble vitamins, phytochemicals, and antioxidants.

 

Zoe "Doctor, I love chickpeas — do they count as legumes?"

 

Dr. Lee "Yes, they're legumes. But chickpeas have a high carbohydrate ratio. We can further subdivide legumes into 'lipid beans,' 'protein beans,' and 'carbohydrate beans.' Lipid beans are high in lipid — like the soybeans used to make doenjang. Protein beans would be like seoritae black soybeans. And carbohydrate beans are chickpeas, mung beans, and peas."

 

Emily "What is a pecan?"

 

Dr. Lee "Pecans look similar to walnuts. They're produced mainly in the United States and Mexico. Native Americans — the original peoples of America — ate a great deal of pecans. According to research, when food was scarce in winter, they sustained themselves for about three months on pecans they had harvested in the autumn. Pecans contain about 72 grams of lipid per 100 grams, and because they air-dry naturally they can be stored long-term. Other ordinary fruits, by contrast, are high in moisture and contain less than 1% lipid, so they don't keep well. We could therefore say that Native Americans practiced a plant-based ketogenic diet for at least three months each year. In nutrition classes, when I have students taste various nuts, pecans are by far the most popular."

 

Everyone is busy taking notes. Suddenly, Zoe raises her hand.

 

Zoe "Doctor, are these the pecans in pecan pie? I once visited the U.S. and remember eating pecan pie."

 

Dr. Lee "Yes — that's right. Pecan pie is delicious, isn't it?"

 

Grace "In the U.S., people make pecan pie all the time. With just a touch of maple syrup, children love it even more. And actually — I made pecan pie for our lunch today!"

 

Everyone "Wow! Wonderful! That sounds delicious!"

Two precautions when eating nuts

Emily "Doctor, are there things to watch out for when eating nuts?"

 

Dr. Lee "Good question. First, you should always soak nuts in water for about 30 minutes and then rinse them before eating. Nuts are so nutrient-rich that they easily attract mold. So whether or not preservatives are present, eating them unwashed isn't a good idea. Soak in water for about 30 minutes, rinse, and dry in the shade or in an air fryer for about an hour — they taste better and feel better on the body. Personally, when I eat unwashed nuts, my lower back hurts. It may be that the liver can't fully detoxify the residues and they move on to the kidneys. With washed nuts, this doesn't happen."

 

Emily "What temperature should I dry them at in the air fryer?"

 

Dr. Lee "I recommend the lowest setting — usually around 80°C (176°F). Drying at high temperatures can cause the lipids to become rancid, which makes inflammation in the body easier. Immune cells get activated easily by rancid lipids."

 

Susan "Then what nutrients are in the third group, vegetables·fruits?"

 

Dr. Lee "The vegetables·fruits group provides various antioxidants, phytochemicals, and abundant water-soluble vitamins."

 

Susan "What is a phytochemical?"

 

Dr. Lee "Phyto means plant, and chemical here can be understood as 'natural medicine.' So phytochemicals are the various natural medicinal compounds found abundantly in plants that benefit human health. They include fragrant compounds — lactones, coumarins, terpenes, phytoncides — and richly pigmented compounds — anthocyanins, flavonoids, quinones, indoles. These can act like hormones in the body, influencing lipid or carbohydrate metabolism, serving as antioxidants, and playing many other roles."

 

Emily "So when planning meals, choosing one from grains, one from protein·lipid, and one from vegetables·fruits gives us a wide range of nutrients?"

 

Dr. Lee "Yes, exactly."

Everyday meals are extremely carbohydrate-skewed and can cause many diseases

Everyday meals are extremely carbohydrate-skewed and can cause many diseases

Dr. Lee "Suppose you go to a celebration where there's cake, noodles, bread, cola, and more cake. What's the main nutrient?"

 

Susan "Ha! It's all carbohydrate. Wow — we really do eat way too much carbohydrate. I never realized."

 

Table 2-3. Foods at a typical celebration are all carbohydrate.

Food	Main nutrient	Result
Cake	Carbohydrate	Carbohydrate excess: diabetes, cardiovascular disease, hypertension, obesity, inflammation, depression, reduced concentration, ADHD, seizures, schizophrenia, etc.
Noodles	Carbohydrate
Bread	Carbohydrate
Cola	Carbohydrate
Japchae (glass noodles)	Carbohydrate
Sweet bun	Carbohydrate
Snack chips	Carbohydrate
Black-bean noodles	Carbohydrate

 

Dr. Lee "A 355 ml can of cola contains about 39 grams of sugar. Since one packet of sugar is 5 grams, that's roughly 8 packets. So although the forms are cake, noodles, bread, cola — the actual nutrient is all carbohydrate. So how can we balance our nutrient intake?"

 

Emily "We could eat nuts."

 

Dr. Lee "Right. If you keep a small bag or container of nuts, you can carry them anywhere. Eating them along with these other foods would help balance the nutrients."

 

Zoe "But wouldn't it look strange to my friends?"

 

Dr. Lee "Use your judgment. And sometimes, sharing nuts naturally becomes an opportunity to pass along good information. It might seem trivial, but the daily nutrients accumulate, and ultimately they often determine our health. The old saying 'habit makes destiny' fits dietary habits perfectly."

 

Grace "Doctor, you said that the ketogenic diet reduces carbohydrates and increases lipids. So in the Three-in-One Method, we should reduce the grains group and increase the protein·lipid group, correct?"

 

Dr. Lee "Yes. That's the heart of the plant-based ketogenic diet."

 

Susan "How much vegetables·fruits should we eat?"

 

Dr. Lee "The vegetables·fruits group is mostly water. The calories aren't very high. So unless you eat a huge amount at once, you can have a wide variety. The U.S. nutrition community recommends about two plates of fresh vegetables a day. For example — what did we eat for lunch today?"

 

Grace "Pecans, almonds, cashews, plus cucumbers and bell peppers with a balsamic vinegar dressing."

 

Dr. Lee "Right. Did anyone feel sleepy after lunch today?"

 

Zoe "No — actually, my mind feels clearer and I'm more focused. Now that I think about it, I always used to feel drowsy after eating rice. But not today. Why is that?"

 

Dr. Lee "When you do a plant-based ketogenic diet, blood flow improves. Oxygen and nutrients reaching the brain also increase. When you eat a lot of carbohydrate, insulin secretion rises, which increases triglyceride synthesis in the body and makes you tired. Carbohydrates have lower energy-generation efficiency than lipids."

Restricting carbohydrate and increasing lipid produces ketone bodies

Restricting carbohydrate and increasing lipid produces ketone bodies

Emily "Doctor, but why does carbohydrate have to be restricted for the body to produce ketone bodies?"

 

Dr. Lee "Good question. The answer is easiest to understand by looking at the TCA cycle in biochemistry. As you can see in the figure, in the TCA cycle the four-carbon molecule oxaloacetate reacts with acetyl-CoA — taking two carbons from acetyl-CoA — to form the six-carbon molecule citrate. Citrate then continues through the cycle, releasing two carbons as CO₂ and generating energy, and converting back to four-carbon oxaloacetate. For this cycle to keep turning, oxaloacetate must continually be supplied — which is done by carbohydrate and protein. But when oxaloacetate is not supplied, acetyl-CoA cannot react and accumulates. Once the concentration is high enough, acetyl-CoA is converted into ketone bodies."

 

Emily "Ah — so it's like two parts that need to be assembled. If one is missing, the other has to be transformed into something else."

 

Dr. Lee "Exactly. Acetyl-CoA is part A, and oxaloacetate is part B. They need to combine. If oxaloacetate isn't supplied, acetyl-CoA is converted into ketone bodies. And oxaloacetate is supplied by carbohydrate and protein."

 

Zoe "Fascinating. Then how much carbohydrate do we need to restrict to produce ketone bodies?"

 

Figure 2-2. The TCA cycle and ketone body production.

When carbohydrate does not supply oxaloacetate, the acetyl-CoA generated from fatty acids cannot enter the TCA cycle and accumulates. Once the concentration is high enough, acetyl-CoA is converted to acetoacetyl-CoA, then to acetoacetate — a ketone body. Acetoacetate is interconvertible with another ketone body, β-hydroxybutyrate. The glutamate produced in the TCA cycle is an excitatory neurotransmitter. In brain cells, the ketone body acetoacetate promotes the conversion of glutamate to GABA. GABA is an inhibitory neurotransmitter that stably regulates excitatory signals.

 

Dr. Lee "Each person's constitution and environment differ, so it's hard to give a single number. But the general standard is 100 grams of carbohydrate per day. As we'll see in case studies later, sometimes 100 grams isn't low enough — some people need to reduce their daily carbohydrate intake to 80, 60, 40, or even 20 grams. To check accurately, you can use a ketone meter. They work much like a blood-glucose meter and can be used at home. Since the human body produces three kinds of ketone bodies that interconvert, there are three corresponding measurement methods. Acetone is detected as a gas in exhaled breath — the cheapest, but slightly less accurate. Acetoacetate is excreted in urine and is measured from urine samples. β-hydroxybutyrate is measured by pricking a fingertip and applying a drop of blood to a small strip — like a glucose meter — and best reflects the blood state."

 

Figure 2-3. Interconversion of ketone bodies.

Acetoacetate can decarboxylate non-enzymatically to acetone, releasing CO₂. It can also be reduced by β-hydroxybutyrate dehydrogenase, with NADH+H⁺ converted to NAD⁺, into β-hydroxybutyrate.

 

Grace "Doctor, looking at the TCA cycle, glutamate is produced. And from glutamate, GABA is produced. Glutamate is known as an excitatory neurotransmitter, and GABA as an inhibitory one. The two work like the accelerator and brake of a car, stably regulating nerve activity."

 

Dr. Lee "Yes — excellent question. We'll cover this more later, but modern people eat carbohydrate-skewed diets, which seem to overproduce glutamate while reducing GABA production. This appears to influence the rising incidence of various neuropsychiatric disorders — seizures, ADHD, schizophrenia, autism, paranoia, panic disorder, and others."

 

Grace "Then a ketogenic diet could increase GABA production?"

 

Dr. Lee "Research suggests yes. Ketone bodies come in three kinds. β-hydroxybutyrate is stable in the blood; acetone is exhaled when in excess; acetoacetate is excreted in urine when in excess. The three interconvert. Research shows that when acetoacetate is present, brain cells increase the conversion of glutamate to GABA (Yudkoff et al., 2008). There are also other mechanisms by which ketone bodies promote GABA production (Calderón et al., 2017)."

 

Figure 2-4. The synthesis of GABA from glutamate.

In the pre-synaptic neuron, glutamate is decarboxylated by glutamate decarboxylase (GAD) into GABA, which is packaged into synaptic vesicles. When calcium ions enter the cell, vesicles fuse with the membrane and release GABA into the synaptic cleft. GABA binds to two types of receptors on the post-synaptic neuron — GABA-A (ionotropic, allowing Cl⁻ influx and generating inhibitory signals) and GABA-B (metabotropic, G-protein coupled). Excess GABA diffuses to nearby glia cells, where GABA aminotransferase (GABA-T) converts it into succinate.

Plant-based ketogenic eating already existed in many traditions worldwide

Plant-based ketogenic eating already existed in many traditions worldwide

Zoe "Doctor, I've been doing yoga for over three years. Recently I've been hearing about Ayurveda, a healing approach connected with yoga principles. In Ayurveda there's a method that uses butter and oils for healing. I think this is also a kind of ketogenic principle."

 

Dr. Lee "Yes — exactly. Ayurveda also uses butter to increase lipid intake. And in Asian traditions, the Sinseonjeon (Tales of the Daoist Immortals) describes byeokgok — abstaining from grains. Byeokgok can be interpreted as restricting carbohydrate. While abstaining from grains, practitioners ate a few pine nuts or beans each day instead — both of which are high in lipid. So the Sinseonjeon writers also seem to have understood, empirically, that a high lipid ratio aids spiritual practice.

"There's also the famous Japanese physiognomist Mizuno Namboku. He was told as a young man that he would die before age 20 unless he spent a year living in the mountains. So he went to live at a temple in the mountains. The condition the head monk set for letting him stay was that he had to live for one year eating only beans (Mizuno, 1812). One year later, looking at his reflection in a stream, he found his face had completely changed. He went on to become Japan's leading physiognomist and earned a court position. Later, he wrote that small portions, vegetarian eating, and regular meals can change one's destiny. To this list, I would add: ketogenic eating."

 

Figure 2-5. Sharing pecan pie at lunch after the morning class.

Pecans are over 70% lipid and very low in moisture, making them naturally a long-storage food. Humans appear to have used storable nuts to survive winters when fresh food was scarce. Even at Paleolithic-era human settlements, oak trees (whose acorns contain about 23.85 grams of fat per 100 grams) have been reported as cultivated.

 

Zoe "It's hard for me to grasp how food could change one's appearance — and one's destiny. Is there a scientific basis for that?"

 

Dr. Lee "Good question. Understanding the diverse functions of hormones may help answer this. Hormones have a property called 'tissue specificity' — a single hormone can produce different effects in different body tissues. Take testosterone, the male hormone. It is sometimes called the 'sex-drive hormone' or 'aggression hormone.' When testosterone levels are high, sex drive and aggression rise (Figure 2-6). In the animal world, animals with high testosterone show greater aggression and dominance — which is why alpha males in chimpanzee groups often have high testosterone.

"In humans, high testosterone tends to produce a deep voice, baldness, hairy face and body, sharper visual perception (and somewhat reduced auditory perception), and more muscle mass. And like hormones, food nutrients influence the body's various forms. A representative scientific report comes from Darwin's finches in the Galapagos Islands. The finches there have remarkably varied beak shapes, and the reason turns out to be that they eat different foods. Depending on the dietary nutrients, the level of a protein called Bone Morphogenetic Protein 4 (BMP4*) varies — and BMP4 in turn changes the beak shape (Abzhanov et al., 2004)."

 

Figure 2-6. Examples of testosterone's diverse effects.

A plant-based diet increases fiber and SHBG and decreases BMI; an animal-based diet increases BMI, leptin, insulin, IGF-1, and growth hormone (GH). These mediators in turn influence testosterone, which then has wide-ranging effects on body and brain — sex drive, mood, voice, hair patterns, dominance, aggression, perception, and more.

 

Susan "How fascinating — that what we eat changes our appearance. In Eastern and Western traditions, physiognomy is the art of predicting personality and destiny from face and body. Perhaps that art is connected to the diverse actions of hormones."

 

Emily "Listening to you, Doctor, I see that across very different cultures, ketogenic eating has been quietly practiced. And recently, science has been confirming the benefits of the ketogenic diet. Thanks to you, I've learned this clearly. From today, I'll start reducing rice in my cooking and adding more beans, and including nuts in our family's meals — I'll try a ketogenic approach."

 

Dr. Lee "That's a wonderful idea. And remember — nuts and beans are high in potassium relative to sodium, so don't forget to also eat unrefined sea salt with them. A teaspoon of unrefined or roasted salt added to rice when cooking is helpful. Nutritionally, sodium and potassium should be consumed in roughly a 1-to-1 ratio. And sodium is essential for the absorption of fatty acids, amino acids, and carbohydrates. See you in the afternoon class."

 

Everyone "Thank you!"

 

* BMP4 (Bone Morphogenetic Protein 4) is a protein involved in bone formation, cell growth, and differentiation. It particularly induces bone formation and is involved in tissue generation and regeneration. Beyond bone, it influences the development and function of various other tissues — including neurons, skin, and blood vessels.

References