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.
"The basic elements I would recommend including, however, would be time, food, amount/portion size and degree of hunger," says Hawkins.
Rebecca Puhl, PhD, director of research at the Rudd Center for Food Policy and Obesity at Yale University, also suggests including the location of the meal: "These details will provide insight into emotional triggers for eating habits, as well as times of day and places where healthy and unhealthy foods are most likely to be consumed."
If you're trying to understand how your emotions relate to your food choices, you might also want to include questions in your diary such as, "How hungry am I?" or "What were my emotions before, during and after the eating episode?"
Keeping track of carbs, fat, and fiber grams will be helpful for people with diabetes and other medical conditions. If you have type 2 diabetes, you might find, for example, that meals high in carbohydrates or meals high in saturated fat may cause you trouble. Or you might discover that your blood sugar levels improve when your meal or snack contains a certain amount of fiber.
Write down other items you think are important, such as how you felt (physically and emotionally) when you finished eating, what and how much exercise you got that day, any medication you took, and your blood sugar results, if you have diabetes.
Food Diary Tip No. 3: Decide How Often to Update
You should write in your food diary at least 5 days a week -- but filling it out every day is best, says Catenacci.
You can fill out your food diary as you go throughout the day, or set some time aside at the end of the day to update it. But experts say your record will be more accurate if you do it right after eating. They also say it's important to record everything – even if that seems painful.
"It can be tempting to avoid recording an unplanned indulgent dessert or binge episode, but this is the most important time to record," Puhl says.
Something to watch out for: As time goes on, dieters tend to become more lax about how often they update their food diaries and go longer after eating or drinking before logging the information.
Food Diary Tip No. 4: Decide How Detailed You Want to Be
If you just can’t bring yourself to fill out a detailed food diary form each day, that’s OK. Just writing a minimum amount of information in your food diary will help you self-monitor. Hawkins says many of her patients believe that if they do not keep a "perfect" food log with every detail, they have failed. She tells them that every attempt they make at recording gets them a step closer to paying attention to their food choices and habits.
Food Diary Tip No. 5: Be Accurate About Portion Sizes
If you're just trying to get a general idea of what, when, and why you are eating, this tip may not apply to you. But if you want to get a precise picture of your intake, make sure the amounts you record in your diary are as accurate as possible, Catenacci says. Measuring out your portions can help give you a picture of what a normal serving size looks like. Kim Gorman, MS, RD, director of the Weight Management Program at the University of Colorado, Denver, advises her clients to measure portions regularly at first, and then on occasion after that.
Food Diary Tip No. 6: Include the 'Extras' that Add Up
The more thorough you are when recording what you eat -- that handful of M&Ms at the office, the mayo on your sandwich, the sauce on your entree -- the more ways you'll eventually find to cut those extra calories. When you look back over your food diary records, look for those nibbles and bites that can really add up. Did you know that 150 extra calories in a day (that could be one alcoholic drink or a slather of spread on your bread) could result in a 15- to 18-pound weight gain in one year?
Food Diary Tip No. 7: Beware of Common Obstacles
Are you embarrassed or ashamed about your eating? Do you have a sense of hopelessness, feeling that it won’t help to fill out a food diary or that weight loss is impossible for you? Does it seem too inconvenient to write down what you eat/drink? Do you feel bad when you "slip up"? These are the four most common obstacles to keeping a food diary, Delinsky says. What's the cure? "All of these obstacles can be overcome by remembering the usefulness of the diaries, not trying to be perfect, acknowledging that slips will happen, and staying motivated to use tools that promote health and well-being," Delinsky says.
Food Diary Tip No. 8: Review What You Wrote
Food diaries are most helpful when you look back and review what you wrote. You can do this on your own or with a therapist or dietitian who can help point out patterns that are keeping you from losing and suggest alternatives to try. "The act of acknowledgment and reflections is the most important piece," says Hawkins.