Wasting (severe thinness) is a common and serious problem among young children in rural Guinea-Bissau. Community Health Agents (CHAs) can help prevent malnutrition by regularly measuring children's growth and advising families on nutritious local foods. However, this practice is not consistently implemented.

This pilot study will test whether implementing Regular Growth Monitoring (RGM) by CHAs every month is feasible and effective in reducing malnutrition among children aged 6 months to 5 years in two rural villages. Investigators will also compare three methods for measuring mid-upper arm circumference (MUAC), which is used to detect malnutrition: the standard WHO tape measure, a photograph of the arm, and a simple bracelet. The goal is to identify which method is easiest for CHAs to use reliably.

Baseline and final measurements will be taken in both villages. One village will receive the monthly RGM intervention first, followed by the second village. Families will also be asked about their experiences with the program through brief questionnaires.

Wasting is prevalent in rural Guinea-Bissau villages and adversely affects child health and cognitive development long-term. Prior work by this team of investigators suggests that regular feedback from Community Health Agents (CHAs) to caregivers, including recommendations of locally available nutritious recipes for at-risk children, may reduce the incidence of moderate acute malnutrition (MAM) and severe acute malnutrition (SAM). However, routine growth monitoring (RGM) has been largely unfeasible at the village level due to measurement complexity and limited training resources. Modern technology and artificial intelligence may help make this more scalable.

This is a proof-of-concept, sequential pilot study conducted in two villages in Guinea-Bissau with which the team has an established relationship. Baseline anthropometric measurements will be collected on all eligible children (aged 6 months to 5 years, without SAM at enrollment) in both villages. Children identified with SAM at baseline will be referred to the local malnutrition clinic and excluded from the study.

One village will begin the RGM intervention immediately after baseline data collection. The second village will begin the intervention after final data collection in the first village. Assignment order will be by PI decision rather than randomization, as required by the collaborating UCSF team members.

During the RGM period, CHAs will screen each child monthly using all three mid-upper arm circumference (MUAC) methods: (1) WHO tape measure (reference standard), (2) arm photograph, and (3) bracelet. Data will be entered into a secure REDCap database. Children meeting SAM criteria (by tape measure) will be referred to tertiary care; children with MAM will receive weekly CHA nutrition education on local recipes. Measurements collected at baseline and end-of-study include: weight, height, MUAC by all three methods, skinfold thicknesses (biceps and triceps), and family demographics.

After study completion, brief questionnaires will be administered to parents, CHAs, and Ministry of Health staff to assess perceived effects, acceptability, feasibility, and preferences among the monitoring methods. This study has been approved by both the Dartmouth College CPHS and the Ministry of Health in Guinea-Bissau.

Inclusion Criteria:

• Children aged 6 months to 5 years residing in one of the two selected villages in Guinea-Bissau
• Caregiver willing to enroll the child in the study (verbal consent provided)
• Caregiver can provide birth certificate or documentation of child's age
• Child does not have severe acute malnutrition (SAM) at the baseline assessment

Exclusion Criteria:

• Children diagnosed with severe acute malnutrition (SAM) at baseline (these children will be referred to the local malnutrition clinic)
• Children whose caregivers do not wish to participate

Deidentified participant data will be stored and made publicly available at an appropriate repository following publication of the primary manuscript. Participant names stored locally in Guinea-Bissau will be retained for 3 years after study completion and then destroyed. The US team will not have access to identifiable participant information.

Following publication of the primary manuscript.

Publicly available deidentified dataset; access details to be determined at time of publication.