Design Factors for Food Supplementation and Nutrition Education Interventions That Limit Conclusions about Effectiveness for Wasting Prevention: A Scoping Review of Peer-Reviewed Literature

We conducted a scoping review to characterize the evidence base for the effectiveness of food supplementation (FS), nutrition education (NE), or FS/NE interventions to prevent wasting among children aged 6 to 59 mo. We aimed to identify gaps in peer-reviewed literature and to develop recommendations for strengthening study designs. We identified 56 unique studies (FS = 21, NE = 19, FS/NE = 16) for which we assessed intervention design factors, implementation context, evaluation methods, and wasting impact. Compared with studies focused on stunting, fewer wasting-focused studies reported weight-for-height z score (WHZ). Midupper arm circumference (MUAC) was more commonly reported in wasting-focused studies (71.4%) than those focused on stunting (36.8%) or wasting and stunting (30.4%). FS studies measured anthropometry (mean, 95% CI) more frequently at every 11.3 (7.8, 14.8) wk than NE interventions at 36.3 (8.8, 62.1) wk (P = 0.036), but not FS/NE interventions at 25.8 (5.6, 49.1) wk (P = 0.138). NE interventions tended to be of longer duration than FS or FS/NE interventions. Only 6 studies followed and measured children after the intervention period ended. Across all studies, 45% reported a significant effect on wasting; these included FS, NE, and FS/NE interventions. The lack of comparability across studies limits conclusions about the effectiveness of specific types of interventions. To build a more unified evidence base for wasting prevention we recommend that future studies 1) report on a consistent set of metrics, including MUAC; 2) attempt to measure change in wasting incidence using more frequent measures; 3) measure wasting prevalence among the general population; 4) follow children postintervention to assess relapse; 5) measure food insecurity and diet quality; and 6) use harmonized protocols across multiple settings. Such efforts to improve study comparability will strengthen the evidence base, may help unite divergent professional communities, and ultimately accelerate progress toward eliminating child undernutrition.