I'm following Atkins, so my list probably isn't of much interest to someone going low fat.
A general comment - BF and I noticed how the grocery bills went up when we started this WOE , because I'm cooking a lot more and we are eating more protein. But at the same time, we don't buy two lunches every day and we only shop 1-2 times per week. Before we would end up at the grocery store almost every day to get some small thing, and almost always get something unplanned and unhealthy as well, like potato chips. So in the end I think it adds up to about the same cost.