At the beginning of the year is the time to start analyzing your expenses such as grocery shopping. How much of your bill (dollars) is going to food and how much is going towards other items? Some grocery stores actually will give you your categories of spending. More likely, you will need to figure it out yourself.
Here are some percentages from a recent shopping trip.
Food includes fruit and Baby items include formula and baby food.
Household Supplies 13%
Baby items 41%
A few impulse buys are included in the household supply amount. Rather than hold an impulse buy to one or two items maybe a dollar amount might be a better approach.