Development of a Method to Observe Preschoolers’ Packed Lunches in Early Care and Education Centers.

BACKGROUND
As early childhood education (ECE) centers become a more common setting for nutrition interventions, a variety of data collection methods are required, based on the center foodservice. ECE centers that require parents to send in meals and/or snacks from home present a unique challenge for accurate nutrition estimation and data collection. We present an observational methodology for recording the contents and temperature of preschool-aged children's lunchboxes and data to support a 2-day vs a 3-day collection period.

METHODS
Lunchbox observers were trained in visual estimation of foods based on Child and Adult Care Food Program and MyPlate servings and household recommended measures. Trainees weighed and measured foods commonly found in preschool-aged children's lunchboxes and practiced recording accurate descriptions and food temperatures. Training included test assessments of whole-grain bread products, mixed dishes such as macaroni and cheese, and a variety of sandwich preparations. Validity of the estimation method was tested by comparing estimated to actual amounts for several distinct food types. Reliability was assessed by computing the intraclass correlation coefficient for each observer as well as an interrater reliability coefficient across observers. To compare 2- and 3-day observations, 2 of the 3 days of observations were randomly selected for each child and analyzed as a separate dataset. Linear model estimated mean and standard error of whole grains, fruits and vegetables, and amounts of energy, carbohydrates, protein, total fat, saturated fat, dietary fiber, thiamin, riboflavin, niacin, vitamins A and C, calcium, iron, sodium, and dietary fiber per lunch were compared across the 2- and 3-day observation datasets.

RESULTS
The mean estimated amounts across 11 observers were statistically indistinguishable from the measured portion size for each of the 41 test foods, implying that the visual estimation measurement method was valid: intraobserver intraclass correlation coefficients ranged from 0.951 (95% CI 0.91 to 0.97) to 1.0. Across observers, the interrater reliability correlation coefficient was estimated at 0.979 (95% CI 0.957 to 0.993). Comparison of servings of fruits, vegetables, and whole grains showed no significant differences for serving size or mean energy and nutrient content between 2- and 3-day lunch observations.

CONCLUSIONS
The methodology is a valid and reliable option for use in research and practice that requires observing and assessing the contents and portion sizes of food items in preschool-aged children's lunchboxes in an ECE setting. The use of visual observation and estimation with Child and Adult Care Food Program and MyPlate serving sizes and household measures over 2 random days of data collection enables food handling to be minimized while obtaining an accurate record of the variety and quantities of foods that young children are exposed to at lunch time.