The authors conducted a systematic review and meta-analysis in order to assess the effectiveness of pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance. The analysis included 21 randomised, controlled trials, reporting data for 8,084 patients. For lifestyle interventions compared to standard advice, the hazard ratio (HR) was 0.51 (95% CI 0.44-0.60), NNTB 6.4 (95% CI 5.0- 8.4). For oral diabetes drugs vs control HR 0.70 (95% CI 0.62-0.79), NNTB 10.8 (95% CI 8.1-15.0). For orlistat vs control HR 0.44 (95% CI 0.28-0.69), NNTB 5.4 (95% CI 4.1-7.6). For the herbal remedy jiangtang bushen vs standard diabetes advice HR 0.32 (95% CI 0.03-3.07), NNTB 4.0 (95% CI NNTH 16.9 to NNTB 24.8). In conclusion the authors note that both lifestyle and pharmacological interventions reduce the rate of progression to type 2 diabetes to a similar degree.