Thanks for the reply Scotty. It turned out that, monetary concerns aside, my wife is very much for purchasing from local shops rather than supermarkets so going grass fed will be easier than expected. However, giving up grains may be a different battle as she feels she needs her carbs to get though the day.
Do other people find exercise is an excellent appetite suppressant? I've found days that i cycle the 7 mile communte from home to work i find it significantly easier during the final couple hours of the fast.