A bad-tempered king

Many years ago there was a king who was very bad-tempered. Everyone was afraid of him. The king was bad-tempered because he was often ill. He was often ill because he ate and drank too much.
"I am always ill", the king told his doctor. "Why can't you cure me?"
The doctor didn't want to tell the king the reason. He knew this would make the king very angry. "I give you the best medicine, Your Majesty", he said, "I do my best."
"Your medicine makes me worse", the king said, "You must cure me before the end of the month or I shall put you in prison. You are trying to poison me".
"Perhaps your food is making you ill", the doctor said. This was a polite way of saying "you eat too much."
"Nonsense," the king shouted. "My cook is the best cook in the world. No I am ill because you are a fool. You do not know how to cure me. I pay you to make me well, but what happened? I have stomachache and a headache everyday. Now go and study your books. Find a cure for my disease or ..."
"Yes, yes, Your Majesty," the doctor said and went to his room. He made a lot of new medicine but it did not cure the king.
At last, a few days before the end of the month, the doctor went into the forest. He wanted to see a wise old monk and ask for his advice.

The wise old monk listened carefully to the doctor's story. Then he said "I understand your problem, doctor. You can not tell the king the truth. He will throw you into prison if you do. You must let the king find out for himself why he is always ill"
"How can I do that?" the doctor asked.
"I have a plan," the old monk said. "Can you get me an invitation to breakfast at the palace?"
"Yes, I can do that easily" the doctor answered.
The next morning the old monk arrived at the palace. He looked very fat because he had cushions hidden under his clothes.
"Come and sit next to me" the king said to him. "You are a holy man and you must have the best food".
The monk sat next to the king and began to eat. He ate and ate and ate.
"I like a man who can eat a lot" the king said.
A few minutes after the meal the monk suddenly fell to the floor.
"Oh! Oh!" he cried. "My stomach! My head! Oh! Oh!"
"Do you have stomachache and a headache, too?" the king asked.
"Always, Your Majesty" the old monk said, and he walked painfully out of the room.
On the last day of the month the old monk went to the palace again. He was slim and healthy:
"You look well," the king said. "Come and eat with me".
"No, thank you", the old monk said. "I eat only one meal a day. I saw your doctor. He is a very clever man and he told me that I eat and drink too much. He was right. Now I do not eat very much and I am healthy. I never have pains in my stomach or head".
"That is very interesting" the king said. "I'll eat and drink less, too. Perhaps it will cure me".
And, of course, it did.