Mark Tremblay

1 Introduction Screen use has rapidly transformed how individuals interact with peers, family and society. The first mobile screen devices became publicly available in 2007 and by 2018, 42% of Canadian 0- to 4-year-olds and 77% of 14- to 15-year-olds owned their own smartphone (Brisson-Boivin 2018). Similarly, in 2010, when the iPad was introduced, only 1% of American children under 8 years of age owned their own tablet.

1 Introduction The Canadian 24-Hour Movement Guidelines for Children and Youth (‘Guidelines’) were the first in the world to integrate recommendations for four movement behaviours in a single public health document (Tremblay, Carson, et al. 2016).

A systematic search of global research using 24-h MB guidelines from June 2016 to July 2024 was conducted, followed by data extraction and analysis This time frame was chosen because the world's first 24-h MB guidelines for children and adolescents were introduced in 2016, and the current review specifically targeted articles that addressed all three 24-h MB guidelines together. Recent reviews were reviewed to identify additional articles.