Schools' green restaurant assessment (S-GRASS): From validating an instrument to identifying sustainable practices in schools food services

Abstract

School food services can potentially promote changes in the food system to make it healthier and more sustainable. They can dictate which foods to buy and how to acquire, produce, and distribute them, favoring the production of meals based on sustainable nutrition. The study aimed to obtain an instrument to identify sustainability practices in school food services, covering the five dimensions of sustainable nutrition. The preliminary instrument's version underwent content validation and semantic evaluation. Reliability was assessed by evaluating 23 school food services for interobserver reproducibility and 148 for internal consistency in the Federal District and the State of Mato Grosso (Brazil). The instrument was composed of 76 items divided into 3 sections (1. Water, energy, and gas supply; 2. Menu and food waste; 3. Reduction of waste, construction materials, chemicals, employees and social sustainability). The instrument showed excellent results in content validation, semantic evaluation, and interobserver reproducibility (ICC = 0.949) and reasonable results for internal consistency (KR-20 = 0.660). Evaluating public and private school food services, they showed low sustainability scores in the general instrument (26.93 ± 4.87) and in all 3 sections (1 = 9.97 ± 1.67; 2 = 9.16 ± 2.54; 3 = 7.80 ± 2.39). Section 3 was the one in which school food services performed the worst. Some practices seem consolidated, such as employee attitudes towards reducing water and energy use, recycling cooking oil, offering vegetables and fruits regularly and encouraging diners to reduce waste. Public and private school food services in the Federal District had better results than those in the State of Mato Grosso (31.86 ± 4.63 versus 25.35 ± 3.76). The instrument has strengths, considering its excellent results for content validation, semantic evaluation, and interobserver reproducibility. For internal consistency, the result is believed to reflect the recent topic within school food services. The low performance of school food services points to the need for specific legislation on sustainability, greater planning and investments at the management level, and the execution and recording of activities at the operational level.