“…We found that 42 (72.4%) meta-analyses included only prospective cohort studies, while 16 (27.6%) meta-analyses included either caseecontrol/cross-sectional studies or a combination of prospective cohort studies and caseecontrol/crosssectional studies. We investigated in total 20 unique outcomes, including 4 mortality outcomes (all-cause mortality [31], breast cancer mortality [32], cancer mortality [3,31], and cardiovascular disease mortality [3,31,32]); 7 cancer outcomes (colon cancer [33], colorectal cancer [33], esophageal adenocarcinoma [34], esophageal cancer [34], esophageal squamous cell carcinoma [34], ovarian cancer [35], and prostate cancer [36]); and 9 other outcomes (all fractures [37], coronary heart disease [38], Crohn's disease [39,40], frailty [41], hip fracture [37], hypertension [38], Parkinson's disease [42], T2DM [43,44], and ulcerative colitis [45]) (Table 1).…”