Embora nunca tenha sido explicitamente confirmado que o Cyberman não come, nunca os vimos comer nada em Old Who ou New Who, e há evidências circunstanciais significativas de que eles não precisam comer.
Minha evidência circunstancial é a seguinte:
1) Mesmo na história de uma meia-mulher meio humana, não havia menção de comida.
TANIZAKI: Some elements have been augmented. Some are still human. Sensory capacity, for instance. Her breathing and hearing appears completely cybernetic. And yet...there's also bare flesh. Amazing. Perhaps 55% augmentation with 45% awaiting completion. Do you think? Or perhaps, maybe 60/40. It's fascinating.
IANTO: Can you make her human again?
TANIZAKI: You took parts from a Cyber conversion unit and modified them into a life support for her? How did you know what to do?
LISA: I told him.
Torchwood - Cyberwoman
Em nenhum ponto deste episódio há qualquer implicação de que ela coma, ou que Ianto tenha esgueirado comida para ela. No entanto, ela está viva há algum tempo apenas por causa do sistema de suporte à vida que criaram com tecnologia cibernética de sobra. A dica obrigatória no início deste episódio de que algo não está certo é uma "fuga de energia interna", não faltando pedaços de comida.
2) Está bastante claro que os Cybermen, tanto no Velho quanto no Novo Que são quase inteiramente robóticos, e o cérebro é geralmente o maior, senão o único, componente orgânico remanescente.
Não restar nenhum outro material orgânico certamente reduziria a necessidade de comida. Se isso elimina ou não a necessidade de comida depende de especulações científicas que não estou preparado para fazer, mas parece seguro assumir que a tecnologia de ficção científica pode preservar um cérebro humano sem qualquer alimento.
KRAIL: Yes, Cybermen. We were exactly like you once but our cybernetic scientists realised that our race was getting weak.
BARCLAY: Weak? How?
KRAIL: Our life span was getting shorter, so our scientists and doctors devised spare parts for our bodies until we could be almost completely replaced.
POLLY: But that means you're not like us. You're robots!
KRAIL: Our brains are just like yours except that certain weaknesses have been removed.
BARCLAY: Weaknesses? What weaknesses?
KRAIL: You call them emotions, do you not?
POLLY: But that's terrible. You, you mean you wouldn't care about someone in pain?
KRAIL: There would be no need. We do not feel pain.
The Tenth Planet
DOCTOR: They were, until they had all their humanity taken away. That's a living brain jammed inside a cybernetic body, with a heart of steel. All emotions removed.
Rise of the Cybermen
LUMIC: The most precious thing on this Earth is the human brain, and yet we allow it to die. But now Cybus Industries has perfected a way of sustaining the brain indefinitely within a cradle of copyrighted chemicals. And the latest advances in synapse research allows cyberkinetic impulses to be bonded onto a metal exoskeleton. This is the ultimate upgrade. Our greatest step into cyberspace.
Rise of the Cybermen
Você pode interpretar essa linha em particular como uma confirmação explícita de que os Cybermen do Mundo Novo / Pete não precisam de comida. Infelizmente, eles nem sempre foram perfeitamente consistentes sobre a coisa dos cérebros orgânicos ...
DOCTOR: Loose thinking. The trouble with Cybermen is they've got hydraulic muscles, and of course hydraulic brains to go with them.
Revenge of the Cybermen
E há até uma instância em que a "parte orgânica" morre.
AMY: And what's a Cyberman?
DOCTOR: Oh, sort of part man, part robot. The organic part must have died out years ago. Now the robot part is looking for, well, fresh meat.
AMY: What, us?
DOCTOR: It's just like being an organ donor, except you're alive and sort of screaming. I need to get round behind it. Could you draw its fire?
The Pandorica Opens
Então, infelizmente, não posso basear nenhum argumento férreo neste ponto, e é por isso que eu disse "normalmente".
3) Parece bastante claro que os Cybermen exigem energia.
KAFTAN: A Cyberman would stand in that form and be, well, revitalised?
VINER: Yes, that's reasonable. These projectors were probably made to fire in neuro-electric potential. Yes, that's it, I think you're right.
Tomb of the Cybermen
Suponho que "disparar em potencial neuroelétrico" é essencialmente a mesma coisa que "recarregar".
DOCTOR: See? Compressed information. Tons of it. That is the history of London, 1066 to the present day. This is like a disc, a Cyberdisc. But why would the Cybermen need something so simple? They've got to be wireless. Unless, they're in the wrong century. They haven't got much power. They need plain old basic infostamps to update themselves. Are you all right?
The Next Doctor
DOCTOR: Took me a while, alot on my mind. (stands and turns around) Let's see, this ship crashed here centuries ago, no survivors, but the systems are dormant waiting for power. And then the council stick a load of new cables right on top of you. Bitey wakes up and channels the power, you start crewing up from the shop as best you can, not enough power, not enough parts.
Closing Time
4) Em New Who, os Cybermen são algumas vezes descritos como "imortais", o que seria estranho se eles pudessem morrer de fome.
CYBERMAN: You are in pain. We can remove pain forever.
LUMIC: No, not yet! I'm not ready.
CYBERMAN: We will give you immortality.
...
DOCTOR: Yeah, but that's it. That's exactly the point! Oh, Lumic, you're a clever man. I'd call you a genius, except I'm in the room. But everything you've invented, you did to fight your sickness. And that's brilliant. That is so human. But once you get rid of sickness and mortality, then what's there to strive for, eh? The Cybermen won't advance. You'll just stop. You'll stay like this forever. A metal Earth with metal men and metal thoughts, lacking the one thing that makes this planet so alive. People. Ordinary, stupid, brilliant people.
The Age of Steel