Using visual plate waste measurement to assess school lunch food behavior.

Data reflecting consumption of foods offered in an elementary school cafeteria were collected over a four-day period prior to and after implementation of a nutrition education program. Two methods were employed to measure plate waste, one involving the physical weighing of the returned foods and the other visual examination of the wastes on each child's tray. The two measurement techniques provided similar data on all food items except for stewed tomatoes. For them the visual method consistently exhibited a higher percent plate waste. The sex of the child influenced the amount of food wasted, with the plate waste of 18 food items being higher for girls than for boys. Plate waste of six food items were influenced by grade level; however, except for one item, there was no consistent trend from lower to higher grades.