There are two basic things to do to get started: Choose the format of your food journal and figure out what things you want to track in it.
When choosing the format of your family's food journal, consider what will be easiest for everyone in the family. Will it be online? And if it is online, will everyone have access to it throughout the day? (Some online food journals, such as MyFoodDiary.com, offer access not only from your computer but via mobile platforms, too.) For some members of the family, a piece of paper or a notebook may work best for jotting down snacks and meals throughout the day while others may prefer to keep a meticulous log in an iPhone app such as Edibles.
The fundamental goal of a food journal is to track the food you and your family eat, how much of it you each eat and when you're eating it. Include basic categories such as type of food, reason for eating (breakfast, lunch, dinner, snack, coffee break, etc.), amount, and date and time. Other categories, such as the number of calories or your mood while eating, might be good additions depending on what your goals are. Counting calories, for example, could help adults pinpoint problem areas that, if addressed, could trim their waistline, but will be difficult for kids to complete. Tracking your mood when you reach for food -- outside of breakfast, lunch and dinner -- could help you identify if you or your kids are snacking due to boredom or if it's out of true hunger. What matters is that everyone participates and tracks the same information.