A picture's worth a thousand words: a food-selection observational method

Area of Science:

• Nutrition Science
• Behavioral Science
• Public Health

Background:

• Accurate measurement of behavior is crucial for designing and evaluating behavior change strategies in social marketing and public health.
• Existing methods may lack the precision needed to capture detailed consumer insights regarding food selection.

Purpose of the Study:

• To develop and validate a photographic method for accurately measuring and describing food-selection behavior.
• To assess the healthfulness of selected meals using a novel classification scheme.

Main Methods:

• Direct observation and photographic methods were employed over one week in a workplace cafeteria.
• A classification scheme based on Australian Dietary Guidelines was used to assess meal healthfulness.
• Inter-rater reliability was assessed for dish classification and photograph coding.

Main Results:

• Photographs captured approximately 27% of observed meals (n=168), with high inter-rater agreement for classification and coding.
• The photographic subset was representative of overall dining room patterns.
• Diners' main dish choices aligned with availability, but side dish selections opposed presented proportions.

Conclusions:

• A rigorous observational method combining direct observation and photography was developed for studying food choice behavior.
• The photographic method is robust, accurate, and yields consistent classifications when paired with a comprehensive food scheme.
• Findings suggest increasing healthy main dish availability and employing targeted strategies for side dishes to improve meal healthfulness.