Obesity and overweight conditions have become major health challenges worldwide. The exploration of effective weight loss strategies is essential. Nudges are currently advancing approaches that represent a new and better method for changing the behaviors of people. However, the effectiveness of nudge interventions on weight loss in overweight people who may be obese has not been synthesized in a systematic manner. In this study, a systematic literature search was performed. Only randomized controlled trials (RCTs) were considered. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated as summary statistics. In total, 25 RCTs involving a population of 5,929 individuals were included. Significant effects of the nudge strategy on weight loss (WMD: -0.96 kg, 95% CI: -1.49 to -0.43), body mass index (WMD: -0.3 kg/m2, 95% CI: -0.41 to -0.19) and waist circumference (WMD: -0.75 cm, 95% CI: -1.23 to -0.27) were observed. The subgroup analysis showed that the reduction in body weight associated with nudge interventions was significant in younger and more obese people. Moreover, the effect of nudge intervention on weight loss weakened over time. Overall, the nudge strategy can promote changes in weight loss, body mass index and waist circumference of adults, albeit at a mild magnitude and in particular types of individuals. Nudge strategies can be recommended to clinical practitioners and policy-makers to promote obesity management.

Objectives: To summarize the evidence from systematic reviews (SRs) and meta-analyses that evaluated the efficacy of ginger in treating any conditions and critically assess the quality of these evidence. Methods: A systematic search of the literature was conducted from inception until February 28, 2019 using the PubMed, EMBASE, Web of science, Cochrane library, and four Chinese databases. Literature selection and data extraction were conducted by two independent reviewers. The quality of SRs was evaluated using the AMSTAR-2 tool. The GRADE system was used to assess the quality of evidence. Results: Twenty-seven SRs were included. The number of included studies were various, range from 3 to 27. The condition with the most included SRs was nausea and vomiting (n = 12, 44.4%). Many SRs showed a promising efficacy of ginger, including nausea and vomiting, metabolic syndrome and pain, while the effect of ginger for platelet aggregation failed to draw a certain conclusion. The quality of SRs was heterogeneous. All of included SRs well complied with the Item 1 ("research questions included the components of PICO") and Item 3 ("explained selection of the study designs for inclusion"). Twenty review failed to provide registration information. Only one SR reported the sources of funding for studies included. Conclusions: In our overview, most of SRs suggest ginger is a promising herbal medicine for health care, which is beneficial for nausea and vomiting, metabolic syndrome and pain. However, considering the limited quality of included evidence and heterogeneity of different clinical trials, more well-design studies are required to confirm the conclusion further.