Can a Food Diary Help You Lose Weight?

What if just by making one change in your habits, you could double your weight loss? It may sound too good to be true, but many experts say that the simple act of keeping a food diary can encourage you to eat fewer calories -- and thus lose weight.

Several studies have shown that people who keep food journals are more likely to be successful in losing weight and keeping it off. In fact, a researcher from one recent study says that people keeping a food diary six days a week lost about twice as much weight as those who kept food records one day a week or less. For the six-month study, published in the American Journal of Preventive Medicine, dieters kept food diaries, attended weekly group support meetings, and were encouraged to eat a healthy diet and be active.

How does writing down what you eat and drink in a food journal work this kind of magic?

For one thing, keeping a food diary instantly increases your awareness of what, how much, and why you are eating. This helps you cut down on mindless munching, says Megrette Fletcher, MEd, RD, executive director of The Center for Mindful Eating.

Food diaries also help people identify areas where they can make changes that will help them lose weight, says Victoria Catenacci, MD, assistant professor of Medicine at the University of Colorado Health Sciences Center.  For example, she says, "people don’t realize how many calories they are obtaining from caloric beverages and snacks, and these can be easy interventions … that can help reduce calories."

Sherrie Delinsky, PhD, a staff psychologist at Massachusetts General Hospital, says food diaries can unveil patterns of overeating. They can also reveal identify triggers to avoid, such as not eating enough throughout the day and then overeating at night, or overeating when drinking alcohol.

For some people, the very fact that they have to record every bite helps deter overeating, Delinsky says. Her clients "often reconsider eating something because of not wanting to write it down," she says.

8 Steps for Food Diary Success

Here are some tips from the experts on how to make a food diary work for you.

Food Diary Tip No. 1: Know Your Reasons

If you know what you hope to gain from your food diary, you can make sure you're recording the type of information that will help you in that area. Fletcher advises people to be clear about their intent, whether it’s to become aware of hidden food triggers, notice problematic eating patterns, or just make sure they're eating a healthy diet. 

Food Diary Tip No. 2: Choose Your Format

Kerri Anne Hawkins, MS, RD, a dietitian with Tufts Medical Center's Obesity Consultation Center,  uses several types of food diary forms for her patients. She tells them to fill out just what works for them; they can even create their own system, like using sticky notes.