Food is also a lot more expensive. You can mitigate this a lot by cooking all your own food and not eating out. Shopping from low cost markets like The Milk Pail http://www.milkpail.com/ will help a lot.

My recommendation for eating cheaply is to make sure to have good collection of spices. It costs a lot upfront (~$40-60) but it will allow you to subsist on really cheap food without going crazy. Living off rice and beans is a lot more fun and tasty when you can make masala rice.