Meiwes has always said his victim "wanted to be eaten" |
Meiwes was convicted of manslaughter and sentenced to eight years in 2004 after admitting killing and eating a Berlin engineer he met on the internet.
But a federal judge ruled the verdict was too lenient, prompting a retrial.
Meiwes insists his victim wanted to be eaten and died "a beautiful death", but prosecutors said Meiwes had a "fetish for human flesh" and could re-offend.
Prosecutor Markus Koehler told the court in Frankfurt that Meiwes should be barred from parole after 15 years, as is usual for those serving life sentences in Germany.
Known as the "Rotenburg cannibal", Meiwes placed an advert on the internet before meeting his victim, 43-year-old Bernd Juergen Brandes.
Defence lawyer
The pair met at Meiwes's home in Rotenburg in March 2001, where they had sex before Meiwes cut off Brandes's penis, which the men then cooked and attempted to eat.
Meiwes later stabbed and killed Brandes, before cutting him to pieces and freezing parts of his body, some of which he later ate.
Fantasies
His defence lawyers argue that Brandes willingly agreed to Meiwes's plans, saying the original advert clearly stated that he was looking for a volunteer to be "slaughtered and eaten".
"This was not murder. His [Brandes's] goal was to be eaten and that meant being killed," defence lawyer Joachim Bremer told the court.
However, Mr Koehler insisted that Meiwes killed Brandes "like a piece of livestock" and was obsessed with power and dominance.
Meiwes has admitted that he still fantasises about killing when he sees pictures of attractive young people, a fact prosecutors used to stress that he remains likely to kill again.
Psychiatric assessments of Meiwes during his time in prison have suggested his behaviour cannot be controlled by therapy, prosecutor Annette von Schmiedeberg told the court.
"I find this extremely worrying," she said.
A verdict is expected later this month.