AIM: To compare non-liquid and clear-liquid diets, and to assess whether the latter is the optimal treatment for mild acute pancreatitis.METHODS: The Cochrane Ubrary, PUBMED, EMBASE,EBM review databases, Science Citation Index Expanded, and several Chinese databases were searched up to March 2011.Randomized controlled trials (RCTs) that compared non-liquid with clear-liquid diets in patients with mild acute pancreatitis were included.A meta-analysis was performed using available evidence from RCTs.RESULTS: Three RCTs of adequate quality involving a total of 362 participants were included in the final analysis.Compared to liquid diet, non-liquid diet significantly decreased the length of hospitalization [mean difference (MD): 1.18, 95% CI: 0.82-1.55;P< 0.00001]and total length of hospitalization (MD: 1.31, 95% CI:0.45-2.17;P =0.003).The subgroup analysis showed solid diet was more favorable than clear liquid diet in the length of hospitalization, with a pooled MD being -1.05 (95% CI:-1.43 to-0.66;P < 0.00001).However,compared with clear liquid diet, both soft and solid diets did not show any significant differences for recurrence of pain after re-feeding, either alone [relative risk (RR): 0.95;95% CI: 0.51-1.87;P =0.88] and (RR:1.22;95% CI: 0.69-2.16;P =0.49), respectively, or analyzed together as non-liquid diet (RR: 0.80;95%CI: 0.47-1.36;P =0.41).CONCLUSION: The non-liquid soft or solid diet did not increase pain recurrence after re-feeding, compared with the clear-liquid diet.The non-liquid diet reduced hospitalization.