Is a picture worth a thousand words…er, calories?

This is Part 4 of my review of iPhone apps that track calories in and calories out (begun on Jan 31st). This week I’ll take a look at two apps that have taken a different approach to tracking calories – using photos of your meals. Is a picture worth a thousand calories?

Are photographic food journals more likely to support attitude and behaviour changes associated with food choices compared to written diet diaries? This was the research question addressed in a 2009 study by Lydia Zepeda and David Deal(1). The authors use both the ABC Theory of Behaviour Change(2) and the Precaution Adoption Process(3) as a framework for their hypothesis. These models offer explanations of why knowledge alone is often unsuccesful at eliciting behaviour change. Zepeda and Deal cite a poll conducted by the Harvard School of Public Health which provides evidence that while Americans believe obesity to be a serious problem, and despite knowing how to maintain a healthy weight, they do not perceive it as relevant to themselves, nor do they take action to make lifestyle changes.(4) They suggest these models explain why self-monitoring in general is helpful for promoting change in dietary behaviours and hypothesize that a pictoral record may trigger even greater awareness of dietary habits compared to a written journal.

Increased awareness and a greater perception of self-relevance is also consistent with a complex systems approach to behaviour change. Self-monitoring, as discussed previously, is a form of feedback, and allows an individual to alter his or her behaviour in order to achieve a desired outcome. Feedback is generally distinguished from information by its ability to elicit change.  Additionally, it is self-determined, such that an individual must identify it as something important to them.(5)

Another reason why a photo diary may have an advantage over a written journal is that it introduces an opportunity for changing the food decision before the food is consumed. In terms of complex systems, this reduces the delay in the feedback loop. A shorter delay may help improve the success of the feedback mechanism. A typical food diary is recorded after a meal. While mobile calorie counting apps and diet diary web sites provide information about a foods caloric content, a photo taken before a meal or snack is consumed provides an immediate visual assessment. Although the exact energy value of a meal is not determined by the photo, it does allow for evaluation of serving sizes.

All subjects were provided with a disposable film-based camera. In addition to taking pictures of each meal and snack, they were also asked to keep a paper diary, in which they recorded all foods and beverages consumed. Zepeda and Deal report that although the majority of the participants found taking photos of the meals “cumbersome” and most preferred the paper diary, the “visual impact of photographs on raising self-awareness was greater for many participants than simply reading words that described their diet”.(1) A photo is taken at a decision point and enables an individual to rethink that choice immediately.

A few quotes from study participants provide examples of how food choices might be affected:

  • I didn’t take the extra potatoes and stuff like that because I didn’t want to take a picture again.
  • I felt like if I had to write things down and take a photo, I was less likely to have a jumbo bag of M&Ms. It curbed my choices. It didn’t alter them completely, but who wants to take a photo of a jumbo bag of M&Ms and write it down?

As discussed by the authors, the use of a film-based camera does add delay to the feeddback loop and use of a digital camera would be preferable. So how can this be improved on? Well, there’s an app for that – two to be exact: PhotoCalorie and Diet Tracker Lite.

PhotoCalorie allows for fast and easy calorie tracking. You have the choice of taking a photo of your meal and typing in foods, or you may simply describe your meal without adding a photo. Photocalorie saves time by allowing multiple foods to be entered all in the same line, separated by a comma. All foods in the PhotoCalorie database are standardized to a single serving. To indicate you’ve had more than one serving, include that in your entry.  For example, the following entry would indicate you’ve consumed 6 oz of chicken breast, 1.5 cups of brown rice, 1 cup of broccoli (fresh or cooked), and 3/4 of a cup of skim milk.

“grilled chicken*2, brown rice*1.5, broccoli*1, skim milk*0.75″

But what is a single serving? The web site provides a detailed description of serving sizes for all food categories as well as tips to help you estimate serving sizes accurately. After you’ve entered the details of your meal, the app uses a sophisicated algorithm to search for foods that best match what you have entered – eliminating the need for you to search through the database yourself for the food.

The app is free to download and try out, but to track data for more than five days, you need to pay for an account at $4.95 per month.

A second app that also uses the iPhone’s camera to track your food intake with a photo journal is Diet Tracker Lite. A unique feature of this app is that it can be set up to automatically take a picture within several seconds of opening the app.  This allows the user to take photos discretely (ensure your ringer is off so you don’t hear the “shutter”). Photos are tagged with the date and time. Once the picture has been taken, you can enter a description or comments to accompany it. However, the app does not provide a database or other means for calorie counting; there is a place to enter the caloric value for a photo, but you need to look this information up elsewhere (another app, or online).

Neither app provides a means to track caloric expenditure, only intake. But by reducing the delay in feedback and causing the user to “think before they eat”, would these apps be helpful for promoting dietary change? According to the results from the study by Zepeda and Deal, yes. However, it is still important to remember another aspect of complex systems – heterogeneity; the feedback that works for some, may not always work for others.

ResearchBlogging.org

Zepeda, L., & Deal, D. (2008). Think before you eat: photographic food diaries as intervention tools to change dietary decision making and attitudes International Journal of Consumer Studies, 32 (6), 692-698 DOI: 10.1111/j.1470-6431.2008.00725.x

2. Guagnano, G.A., Stern, P.C., & Detiz, T. (1995) Influences on Attitude-Behavior Relationships – A Natural Experiment with Curbside Recycling. Environment & Behaviour. 27 (5), 699-718 doi: 10.1177/0013916595275005

3. Weinstein, N.D. (1988). The Precaution Adoption Process. Health Psychology. 7 (4), 355-86  http://www.ncbi.nlm.nih.gov/pubmed/3049068

4. Blendon, R.J., et al. (2005) Harvard School of Public. Health Obesity Poll June 23–28, 2005. http://www.hsph.harvard.edu/news/press-releases/archives/2005-releases/press07142005.html

5. Wheatley, M.J. and M. Kellner-Rogers (1999) What do We Measure and Why? Questions About The Uses of  Measurement. Journal for Strategic Performance Measurement.

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