“…Figure 3 presents the risk bias assessment for cross-sectional and case-control studies. In relation to the 32 cross-sectional studies, (26, 27, 29, 31-38, 41-46, 48-52, 55, 56, 58, 61-67) , only nine (26,32,33,35,37,44,49,55,58,63,67) were classified as having low risk of bias. The main methodological problems were the evaluation of the UPF without valid and reliable measures (26,29,31,34,36,37,41,44,46,56,58,62,(64)(65)(66)(67) , and without considering the main confounders or established appropriate strategies to deal with them.…”