In Yakuzen, all foods are categorized into five natures: hot, warm, neutral, cool, and cold.
However, these natures are not based on the actual temperature of the food, but on how they affect the body and how the body responds after consumption.

Hot and warm-natured foods help warm the body, with hot foods having a stronger warming effect.
They are suitable for people who are sensitive to cold, have weak digestion, or experience menstrual cramps.

Cool and cold-natured foods help clear excess heat from the body, with cold foods having a stronger cooling effect.
They are suitable for people with excessive internal heat (yang energy), which may manifest as symptoms like red eyes, irritability, constipation, thirst, or excessive sweating.

Neutral foods neither warm nor cool the body, making them easy to combine with other ingredients.
They help balance the effects of hot and cold foods.