“…Six of the studies (Chan and Lo 2017;Kempen and Steyn 2016;Brownell et al 2006;Leko et al 2015;Simpson et al 2016;Rinaldi, Averill, and Stuart 2011) are small-scale studies, while the rest are large-scale studies. Six studies only implicitly describe how many participants were included because the cases include one or more schools or programmes (Kempen and Steyn 2016;Juma, Lehtomäki, and Naukkarinen 2017;Carrington, Deppeler, and Moss 2010;Wesson, Voltz, and Ridley 1994;Paul, Duchnowski, and Danforth 1993;Nevárez-La Torre and Sanford-De Shields 1999).…”