<p>Based on what has been revealed, it would seem that she needs to eat a brain once every thirty days (a month, basically). If she doesn't get one within that time period, she risks becoming like the Romero zombie of old. </p>

Source?

<p>in an episode, Blaine shows a brain to Mr.Boss, and says "you know what you're looking at?", to which he replies "a brain?" and Blaine corrects him with "You're looking at 20 000 dollars, one of these can last a zombie a full month" </p>

once a month but shes eting one every episode and whats with the powers and taking on traits of the host even tho this does happen in real life when people have transplants and whats with the abilties ???

<p>She would have to eat a brain every month in order not to turn into a Romero, but there's also the aspect of solving murder cases with her abilities. It's not always clear how much time passed between two episodes, most likely only rarely a full month, so I think for a large part she attends to brains to solve cases. Plus it seems most of the time she doesn't eat a full brain, so it would last her accordingly less long. Also note that there have been times she ate another brain (or tube) to get an unpleasant personality out of her mind. </p><p>As for the gaining abilities part, well, isn't all personality stored in the brain? Liv literally consumes the brain, and thus whoever's personality it was, including their memories, experiences, abilities, etc. But yeah, that's just how the story works, not something you could reproduce in the real world. It's a zombie thing ;) </p>