2.2. Participants and Intervention
confusion
EGG ALLERGY
We enlisted students from six rural primary schools, with eligibility requirements stipulating an age range of 8 to 14 years. Individuals with an egg allergy were excluded. Cluster randomization was employed, with each classroom in every school being assigned to one of the three groups. This approach aimed to minimize group confusion and maintain adherence to the groups. All six schools were encouraged to offer similar school lunch menus, when possible, to standardize caloric and nutritional content in accordance with the national school lunch program [Before the intervention, all participants were instructed to maintain their usual egg consumption and dietary cholesterol intake for four weeks (washout period [week − 4]). Those in the intervention groups (WE and PS) continued their normal dietary routines. The intervention was administered individually to each classroom during regular lunch hours. The WE group received ready-to-eat commercial menus (S.W. Foodtech., Co., Ltd., Bangkok, Thailand) comprising items like hard-boiled whole eggs, scrambled eggs, stewed eggs, omelets, etc. The PS group was provided with ready-to-eat commercial options like egg white or chicken sausages. On average, WE participants received 800 to 850 kcal/day, 2100 to 2260 mg of dietary cholesterol, and 70 to 80 g of protein, while PS participants were given 810 to 850 kcal/day, 50 to 220 mg of dietary cholesterol, and 70 to 80 g of protein on school days. Control group participants received standard school lunches aligned with the Thai school lunch program. No group received additional meals or supplements on weekends. Throughout the study, participants underwent follow-up assessments at baseline, 14 weeks, and 35 weeks.