Many human cultures have practiced cannibalism throughout history; this isn't in dispute. But it's generally a ritualistic practice, or an act of desperation. I'm not aware of any cultures that have ever engaged in cannibalism as an exclusive form of sustenance, either because the people preferred human meat, or had no access to animals to hunt.
Before someone tackles your question, here's a few links to earlier, similar questions, that you might find useful in the meantime:
Has there ever been widespread cannibalism?