Using photographic food diaries to assess eating patterns of school-aged students

Assessing dietary patterns of school-aged students is challenging. One methodology that has shown promise in recent studies is the use of photographic food diaries. Initial studies have been conducted in tightly controlled situations, with selective student populations. This methodology has not been validated in less-controlled settings, or with low-income students. A pilot study was conducted to test a photographic food diary methodology with schoolchildren in a low-income community. Students in the gardening/nutrition class at Waimanalo Elementary/Intermediate School were provided with disposable cameras and instructed to photograph everything they ate for three days. Students were also given food logs to document each photograph, and record any foods consumed but not photographed. Both were coded and analyzed for content. Eight coding categories were developed: fruit/vegetable, legumes, protein, starch, dairy, mixed dish with fruits/vegetables, mixed-dish without fruits/vegetables, and limited-nutrition foods. Drinks were categorized either as nutritive (milk, juice, water) or limited-nutrition. Inter-rater reliability (Kappa >0.70) was assessed for each of the coding categories. Starch was the most photographed food group (28.0%), followed by limited-nutrition snack foods (21.2%), and fruits/vegetables (20.1%). Limited-nutrition drinks (11.1%) were photographed more than nutritive (8.5%). Students submitted an average of 8.7 photographs, with substantial variation (SD=6.5, range 1-27), and data from food logs were often missing or incomplete, suggesting that incomplete documentation may be a problem in uncontrolled environments. Using photography to assess children's dietary intake is promising, further refinement of the methodology is needed to use this methodology in community settings.