According to a September 2011 article in the Journal of Financial Planning, "...about three-quarters of advisers (73 percent) report that their clients stretch the truth when it comes to living beyond their means; the same number of advisers say that lifestyle is the top roadblock to a secure financial future..." [Principal Financial Group study]
My own experience reflects that 90% of spending is a result of a client's lifestyle choices. Mainly, the housing costs and the transportation costs. Once the major decisions on where to live and what to drive are made, (and the taxes, interest and insurance premiums that go with them) we work for that remaining 10% of "fun".
Indeed, food and clothing and other areas are important to consider and manageable, too, but...
About 10% of spending is on those very controllable areas of dining out, entertainment (movies, fast-food, etc.), vacations, short trips, gifting (birthdays, Christmas, friend's wedding and baby showers and their kid's birthdays, etc.) and that infamous "other miscellaneous purchases" (housing decorations, ATM cash) category.
Know where your money really goes.