Table 1.

The 10 selected Generation Healthy Kids school-based intervention components: aims and content

Intervention kick-off

Delivered by the research group: Family evening A three-hour family evening for the children, parents, and siblings with information, tips, exercises, and games related to both food and nutrition (30 min), physical activity (30 min), and screen media habits (30 min). The goal of the event was to ‘kick start’ the intervention at school. The family evening included free dinner to motivate participation

Food and nutrition

Delivered by school staff: Midmorning snack & cold, pre-prepared do-it-yourself lunch at school four days a week The meals were based on the national Danish food-based dietary guidelines [30]​ and the Nordic Nutrition Recommendations [31]​ and sought to promote a balanced energy intake and increase the intake of wholegrains, fruits, vegetables and legumes, and fish, and reduce the intake of sugar The lunch was accompanied by health pedagogical principles for school staff to promote ‘the good school meal situation’: 1) school staff as role models, e.g., focusing on the meal, eating with the children, guiding the language around the food (positive conversations), and encouraging the children to taste; 2) involvement of the children, e.g., the children take turns being ‘table heroes’ setting the table, presenting the food to the class, etc., and all children eat in small table groups sharing the food; 3) sufficient time for the children to e.g., eat enough, put everything on the plate and investigate new food with all senses, and experience class community during the meal; and 4) Parental support, e.g., parents should not provide additional lunch from home [32, 33] Delivered by the research group: A cold-water dispenser at school & a reusable water bottle for each child To encourage water consumption

Physical activity

Delivered by school staff: 3 × 40 min per week of organized vigorous physical activity during school hours (FIT FIRST 10) The sessions encompassed modified and varied sporting activities​ and games promoting motivation, active involvement of all children, and high intensity. These 40-min sessions were developed to achieve at least 30 min of varied, vigorous activity in relation to cardiopulmonary and musculoskeletal loading for all children, irrespectively of sex, fitness levels, skills, and prior experience with sporting activities, and to promote joy through play-based activities and to challenge the children’s motor competences and physical capacity adequately [34] Delivered by the research group: Packages of loose play and sports equipment for school recess for participating school classes To increase the children’s daily amount of physical activity [35, 36], the participating school classes received skipping ropes, frisbees, street chalk, cones, handballs, footballs, and tennis balls for use during recess

Sleep and screen media habits

Delivered by school staff: Screen media habits assignment in class To make the children reflect on their screen media habits, school staff were asked to conduct the assignment ‘The Digital Barometer’ from The Danish Media Council [In Danish: ‘Medierådet’] with the children during school hours Delivered by the research group: Three inspiration sheets for parents on screen media habits and sleep Parents received three inspiration sheets introducing knowledge about and recommendations for screen media habits and sleep, potential tools to address knowledge and comply with recommendations, as well as suggestions for child and parent activities to support dialogues about sleep and screen media habits Parent workshop on screen media habits A three-hour workshop with information and dialogue focusing on children’s screen media practices. The workshop presented the results of the assignment ‘The Digital Barometer’ which the children completed during school hours. The goal of the workshops was to increase parent knowledge on their own and their children’s screen media practices, strengthen the dialogue with other parents, their own child, and between children within the provided subject (e.g., evening screen media use). The workshop included free dinner and childcare to motivate participation