Why do I feel so tired after eating?

Everyone is a little slower after a large lunch, and the tradition does not read that as anything. What it reads is the person who is heavy after every meal, who cannot keep their eyes open at two, whose afternoon is lost to a plate of rice. In its picture of the body the spleen is the organ that takes what the stomach has received and lifts it, as qi, up to the head and out to the limbs. If the spleen is weak, a meal does not lift; it sinks, and the head and limbs go without until the middle has finished.

Three things produce that, and they are usually found together. The spleen may simply be short of qi, so that every meal is more than it can carry. It may be damp, clogged with the residue of too much sweet, cold and rich food, so that it carries slowly. Or the meal may be sitting undigested, which the tradition calls food stagnation and which anyone who has eaten too much at a wedding will recognise.

The Suwen gives the mechanism in the chapter on the greater yin and the yang brightness, which is to say the spleen and the stomach: the limbs are fed from the stomach, but only by way of the spleen. A weak spleen is a stomach full of food and limbs full of nothing.

The physician who made the spleen the centre of his whole medicine was Li Dongyuan, whose Treatise on the Spleen and Stomach of 1249 has the phrase in the plate caption above. He was writing in a besieged city about people worn down by hunger, fear and overwork, and he described what we still see: the person who is sluggish, loves to lie down, and whose limbs will not gather themselves.

Three pictures, and a fourth that is not a picture at all. The tongue and the stool decide between the first three.

• Lunch smaller than you think, warm, and eaten sitting down away from the desk. The tradition’s rule of seven parts full, 七分饱, is for exactly this meal.
• Less sweet and less white: bread, rice and noodles in a smaller heap, with something warm and savoury beside them.
• A walk after. A hundred steps after the meal, 饭后百步走, is a proverb older than any of us, and it is the single most reliable thing on this page.
• No cold drinks with the meal, and no fruit straight after it. The spleen lifts warm food and sinks under cold.
• A rest at noon, if you must, of twenty minutes, sitting. Longer, and you wake heavier than you lay down.
• Chew. The stomach receives; the spleen lifts; neither does the work the teeth were for.

None of that is a promise, and we make none. It is the floor, and the size of lunch is the plank.

• Ginger 生姜, fresh, in the cooking and in a cup before the meal, for the thin-and-spent picture: it warms the middle so that the spleen has something to lift with.
• Tangerine peel 陈皮, a piece in hot water after lunch, for all three pictures. The Bencao Gangmu says it supplements with the supplementers and moves with the movers.
• Poria 茯苓 and Job’s tears 薏苡仁 in the morning congee, for the heavy-and-foggy picture: both drain the damp without heating.
• Jujube 大枣, three or four in the same congee, for the thin-and-spent.
• For the full-and-sour picture: a smaller supper and nothing else. Hawthorn, 山楂, is the tradition’s answer to a meal that will not move, taken as a sour tea.

Four finger-widths below the kneecap, a thumb’s width outside the shin bone, is Zusanli, Stomach 36, 足三里: the stomach channel’s great point, which the tradition presses to raise the qi of the middle. Thumb pressure, a minute each side, on the walk after lunch. It is not a needle and it is not a claim about outcomes.