Our grocery budget is $150 pr week. All meals fall under this category, including eating out and take aways. Depending on where you live, you may pay more or less on groceries, so determining the ideal dollar amount for your family will take some research and trial and error. We make it easy for ourselves by having two weeks' worth of grocery money in a jar, "as seen on TV." It's a lot harder to go out to a restaurant or order in a pizza when you have to take that money out of a jar, and see what's left for shopping in a grocery store.
Our food budget has always been manageable, but I see how much more food we are eating, and how we aren't spending any more money than before. We even had a small ($10) surplus last week. Typically, we would spend $40 a week on meat or fish. That has dropped to about $10-$15. As our portions are that much smaller, a ham, or roast lasts days longer.
The majority of foods permitted on CFG are unprocessed. Buying fruits and vegetables that are in season not only makes sense, but keeps money in your pocket as the prices for these will generally be lower. We have been thoroughly enjoying the berries and fruit available right now, and are researching the best options come winter, when fresh won't be available. You will find your trips to the grocery store will exclude (for the most part), the inside aisles. Our province includes a tax on groceries, in the simplest terms, those groceries that are highly processed (i.e. chips, frozen foods). My last two shops had zero tax on the bill. We all love not paying tax!
CFG not only seems to create a healthy lifestyle in regards to diet, but a much healthier lifestyle for your budget.