1. Unused methods.

Method	Approach
Measures of treatment effect	Rates If rates represent events that could have occurred more than once per participant, we will report the rate difference using the methodologies described in Deeks 2011.
Unit of analysis issues	Cluster‐randomised studies Where possible, we will estimate the intra‐cluster correlation co‐efficient (ICC) from trials' original data sets and will report the design effect. We will use the methods set out in the Cochrane Handbook for Systematic Reviews of Interventions to calculate the adjusted sample sizes (Higgins 2011b). We will use an estimate of the ICC derived from the study (if possible), from a similar study or from a study of a similar population. If we use ICCs from other sources, we shall report this and conduct sensitivity analyses to investigate the effect of variation in the ICC (see Sensitivity analysis). If we identify both cluster‐RCTs and individually randomised trials, we plan to synthesise the relevant information. We will consider it reasonable to combine the results from both if there is little heterogeneity between the study designs and the interaction between the effect of intervention and the choice of randomisation unit is considered to be unlikely. We will also acknowledge heterogeneity in the randomisation unit and perform a sensitivity analysis to investigate the effects of the randomisation unit (see Sensitivity analysis).
Assessment of reporting bias	If we include 10 or more studies in the meta‐analysis, we will investigate reporting biases (such as publication bias) using funnel plots. We will assess funnel plot asymmetry visually, and use formal tests for funnel plot asymmetry. For continuous outcomes, we will use the test proposed by Egger 1997. For dichotomous outcomes, we will use the test proposed by Harbord 2006. If any of these tests detect asymmetry, or if it is suggested by a visual assessment, we will perform exploratory analyses to investigate it.
Subgroup analysis and investigation of heterogeneity	We will conduct the following subgroup analyses. Anaemia status of the participants at baseline: anaemic versus non‐anaemic versus mixed/unknown/unreported Baseline BMI of the participants: low BMI (< 18.5 kg/m²) versus normal BMI (18.5 to 24.9 kg/m²) Delivery strategy: health facility versus provided in community versus mixed/unknown/unreported Duration of intervention: < 3 months versus 3 to < 6 months versus 6 to 9 months Setting: stable versus emergency versus mixed/unknown/unreported. We used the Inter‐Agency Standing Committee's (IASC) definition of emergency (IASC 1994): a situation threatening the lives and well‐being of a large number of people or a very large percentage of a population and often requiring substantial multi‐sectoral assistance.
Sensitivity analysis	We will conduct sensitivity analyses to assess the robustness of the results to the following. Removing studies at high risk of bias (studies with poor or unclear allocation concealment and either blinding or high/imbalanced loss to follow‐up) from the analysis Different ICC values for cluster‐randomised studies (if these were included) Studies with mixed populations in which marginal decisions were made (specifically, we aimed to conduct a sensitivity analysis for studies that were conducted in multiple settings, to assess whether the impact on any outcome was marginal) A fixed‐effect model

ICC: intra‐class correlation coefficient.