How can I hack in health?

playerHp is your current health, not the maximum possible health. Your maximum health is determined by how many candies you have eaten. There are a few variables that seem to deal with this:

number gameCandiesEatenAccumulated=0, 
number gameCandiesEatenCurrent=0, 
number gameCandiesEatenMax=0

However, just by modifying gameCandiesEatenCurrent I was able to boost my hp. Remember: you'll need to add a lot of candies to boost your health significantly!

You can also turn up the 'gameGiftHealth=0;' to 'gameGiftHealth=2000;' That is what I do. It is also located almost right above the 'number playerHp'