“…The majority of the studies was conducted in North America or Europe (85%, n = 28) [ 47 – 65 , 68 , 71 – 77 , 79 ]. Most of the studies were intervention studies without a control group and with at least two measurement time points (n = 15) [ 47 , 50 , 51 , 53 , 55 , 57 , 59 , 61 , 64 , 65 , 72 , 73 , 76 , 77 , 79 ]. Eight papers reported randomized controlled trials [ 48 , 52 , 54 , 66 – 70 ], six papers described non-randomized controlled intervention studies [ 49 , 56 , 58 , 63 , 75 , 78 ], and four papers reported uncontrolled cross-sectional intervention studies [ 60 , 62 , 71 , 74 ].…”