Seeing is believing. Studies have shown that people who keep a daily food journal lose more weight than those who don’t. In the early days of keeping a food journal, you can look back a day or a week at a time to assess your food choices and quantities and see why your weight is going up, down or staying the same.

Food journals are all about accountability, says Elisa Zied, a registered dietitian in private practice in New York. “Being accountable to yourself empowers you to make changes, to see where there's room for improvement,” she says. “It’s very easy to eat and not give it much thought, but when you put it on paper, it may shock you to see how much you take in.”

What to Record

Resolve to write in your diary every time you eat something, so it will become a habit that will serve you well. For best results, record the following:

Every bite that goes in your mouth. That means meals, snacks and even samples you’re given at the grocery store. And tally the calories you consume. Not sure how many calories are in that cookie or slice of cornbread? Check out the U.S. Department of Agriculture's National Nutrient Database

Where and when you eat. You might find a pattern of late-night or between-meal snacking. Some people lose their discipline when dining out, and some find they tend to get excess calories eating in the car or sitting at their desk.

How you are feeling. Emotions can drive us to eat more than we should. If you have a frustrating day at work, are worried about your marriage or pressured by a never-ending to-do list, write it down.

Who you are with. Some people eat with gusto when alone; others when in a social setting.

The circumstances. If you eat a bowl of ice cream, jot down if you had the craving for two nights and finally gave in. If you ate a second helping of mashed potatoes because you thought they would otherwise go to waste, put it in writing.

Activity and exercise. It’s not only what goes in that counts. The calories you burn by walking, gardening or working out make a difference in whether you lose or gain. For a free list of calories expended for a variety of activities, visit nutristrategy.com.

Your sleep schedule. If you sleep too little, you might eat too much.

Changes in weight. You’ll want to record your pounds from week to week, and consider keeping track of your body measurements, too. Measure your hips, waist, chest, thighs and arms regularly, and watch the inches come off.

Tip: Think of your food journal as you would a checkbook.

Imagine you get “paid” a certain amount of calories every day. Those calories are your account balance. As you eat during the day, deduct from your balance the calorie count of everything you eat to monitor your “spending” habits.