“…Thirteen reviews considered diet, 17 , 23 , 25 , 29 – 32 , 34 – 38 , 40 four considered physical activity, 16 , 18 – 20 and eight considered both. 21 , 22 , 24 , 26 – 28 , 33 , 39 Eighteen reviews summarized quantitative evidence only, 16 , 18 – 21 , 24 – 30 , 32 – 34 , 38 – 40 including four that conducted meta-analyses, 18 , 21 , 29 , 38 and one that used modelling techniques. 32 Four reviews incorporated both quantitative and qualitative evidence, 22 , 31 , 35 , 37 including one that used a meta-ethnographic approach.…”