Eating watermelon during the cold winter can cause stomach pain, so avoid eating or eat less off-season foods. Plants that grow in water, damp, swampy places must have water-resistant properties. On sunlit hillsides, most of the medicinal herbs growing there are heat-clearing because they can resist heat, and resisting heat means they are cold in nature.

Plants like Codonopsis pilosula, Polygonatum odoratum, and Polygonatum sibiricum that grow on the shadier hillside have yin-nourishing effects. In deep mountain valleys where ice and snow don’t melt, Aconite grows, its lateral roots are Aconite, and it develops resistance to cold and moisture, treating rheumatoid arthritis and symptoms of genuine Yang Qi deficiency, such as feeling cold all over and cold hands and feet.

It’s not just plants; animals are the same way."

Lu Xuan continued, "Ants, which burrow in damp, dark underground areas, don’t get arthritis or rheumatoid arthritis. Ants have anti-rheumatic properties, so ants are used to treat rheumatoid arthritis with certain effectiveness.

There’s a type of waterbird that lives by the water, often eats fish from the water, and frequently stands in the water, gaining some resistance to moisture. Some waterbirds with relatively weak constitutions, when they get rheumatoid arthritis, fly near the ant nests, using their wings to fan the ants. The irritated ants bite the waterbird, which spreads its feathers to let the ants bite it, receiving free treatment, and after getting ant acid injections, the bird’s arthritis improves...

These are closely related to the yin and yang concepts in Traditional Chinese Medicine. Naturally, besides the ecological environment, an animal’s intrinsic breed is also very important in determining the yin and yang nature of a food or medicine.

For animals, there are some special places to judge their yin and yang nature. Take ducks, which are often in the water. Although water is yin, ducks should be yang, but actually, ducks are not yang; they are yin and have yin-supplementing effects. The reason is that ducks move in the water and absorb the yin Qi from the water, thus they belong to yin.

Chickens running on land gain warmth from the sun and are therefore yang in nature.

Judging the yin and yang attributes of food or medicine, apart from looking at its environment, the feeling after consumption is more important.

Since both medicine and food have yin and yang distinction, naturally, people’s constitutions are also divided into yin and yang."

At this moment, Lu Xuan got to the main topic.

Plants are divided into yin and yang, animals are divided into yin and yang, people naturally are also divided into yin and yang.

It’s just that, compared to plants and animals, the yin and yang differentiation in humans is not so obvious or simple.

"What kind of people belong to yang constitution, and what kind of people belong to yin constitution? How can people with different constitutions adjust the yin and yang balance through diet to maintain health?"

Lu Xuan raised several questions, looking up at the young woman in front of him.

Sensing Lu Xuan’s gaze, the young woman thought for a while, hesitantly saying, "Is it similar to how we judge plants and animals?"

"More or less."

This answer, Lu Xuan found hard to say wrong, but also hard to say right, after all, the young woman wasn’t wrong, just taking a shortcut.

"Simply put, if a person is particularly excitable, afraid of heat, hyperactive, and extroverted, such traits indicate a yang constitution.

If a person is particularly afraid of cold, introverted, calm, and less active, they belong to a yin constitution. For yang-constitution people, we use yin food to adjust; for yin-constitution people, we use yang food to adjust."

"Of course, this is just one method of judgment."

"Are there other judgment methods?" The young woman frowned.

"Naturally."

Lu Xuan explained, "Personality is just one aspect, and it’s hard to fit all situations, so we need to use other methods to judge.

If a person is often cold, with cold hands and feet, and eating slightly cold food causes diarrhea, this is not just a constitution issue but also a deficiency in Yang Qi, requiring medicinal adjustment.

Cold hands and feet, fear of cold, if accompanied by palpitations and heart rate issues, indicate heart yang deficiency.

If accompanied by sore waist and knees, reduced libido, or even impotence, it’s kidney yang deficiency. If there’s bloating, frequent diarrhea, and cold foods cause diarrhea, it’s spleen yang deficiency.

Based on different conditions, medicinal treatment is used. If someone has dry mouth, nasal dryness, irritable heat of the hands and feet, scanty urine, and dry stool, these are signs of yin deficiency.

If accompanied by palpitations, it’s heart yin deficiency; if accompanied by sore waist and knees, it’s kidney yin deficiency; if with cough and scanty phlegm, it’s lung yin deficiency. In such cases, relying solely on the yin and yang properties of food cannot correct the imbalance, and medicine is required.

This is the main reason why dietary supplements often fail to achieve therapeutic effects, as although dietary supplements are mild, they rarely achieve the effect of curing diseases."

"However..."

Lu Xuan shifted his tone, continuing, "Using medicine to correct the human body must not go overboard, as excess leads to the opposite effect.

The "Inner Scripture of the Yellow Emperor" says, ’Excessive yin causes yang illness, excessive yang causes yin illness. Excessive yang causes heat, excessive yin causes cold. Excessive cold leads to heat, excessive heat leads to cold.’

If you go too far with yin, cold medicine, it will consume your Yang Qi, leading to cold conditions."

"For example, I heard a story before, where a young man drank some water while swimming, went home with a stomach ache, tenesmus, and bloody diarrhea. Hospital tests pointed to acute dysentery. Later, a Traditional Chinese Medicine doctor diagnosed it as a yang heat excess condition, with a slight fever, prescribing cold, yin medicine. After taking the medicine for a day, the fever subsided, and in two or three days, there was no more diarrhea. After completing five doses, he was basically cured.