The review question was clear, and inclusion criteria were sufficiently detailed to allow replication. Two relevant databases were searched, and attempts were made to minimise language bias. The review process was potentially subject to error and bias at the study selection stage; the process of data extraction was unclear.
The absence of any reported quality assessment of included trials meant that their reliability was uncertain. Trial details were presented. High statistical heterogeneity was evident for the primary outcome ( total gestational weight gain). The results of the planned sensitivity analysis were not reported. This meant that it was unclear whether statistical pooling of these trials was appropriate.
The authors' conclusion reflects the evidence presented, but the reliability of their conclusion is unclear.