Read Jeremiah 52:34 Using Other Translations
And for his diet, there was a continual diet given him of the king of Babylon, every day a portion until the day of his death, all the days of his life.
and for his allowance, a regular allowance was given him by the king according to his daily need, until the day of his death, as long as he lived.
So the Babylonian king gave him a regular food allowance as long as he lived. This continued until the day of his death.