Globally, populations are experiencing increases in the double burden of malnutrition, commonly defined as maternal overweight/obesity and child stunting in the same household. This study will evaluate an integrated intervention combining food supplementation for pregnant and postpartum women and their infants with behavioral counseling to promote healthy maternal weight, nutrition, physical activity, and infant feeding practices. The goal is to reduce the double burden of malnutrition in rural Indigenous communities in Guatemala.

K'ASLEM (meaning "life" in the Kaqchikel Mayan language) is an individually randomized, parallel-group Hybrid Type 1 effectiveness-implementation clinical trial conducted in Indigenous Maya communities in Guatemala that have among the world's highest levels of double burden of malnutrition. The trial will enroll 766 pregnant women aged 16 years or older before 28 weeks gestation with 1:1 allocation to intervention and comparator arms. The intervention arm will receive two integrated interventions: (a) food supplementation for pregnant and postpartum women and for infants and (b) behavioral counseling to optimize maternal weight and promote healthy nutrition, physical activity, and infant feeding practices. The comparator is enhanced usual care, which includes routine government prenatal and postnatal services along with care navigation and provision of fortified flour for infants. Mother-child dyads will be followed until 12 months after birth. Co-primary outcomes are maternal weight and child length-for-age at 12 months after birth. Complementing these trial outcomes, the study will collect mixed-methods data on implementation outcomes and apply implementation mapping to develop strategies for future scale-up. The trial will also include an economic evaluation to inform policymakers of costs and cost-effectiveness. A major feature of the trial is a focus on pragmatism and fairness, working to enroll vulnerable families from rural Guatemala who stand most to benefit from the intervention but who are commonly excluded from clinical trials.

Inclusion Criteria:

• Pregnant women aged 16 years or older
• Gestational age less than 28 weeks

Exclusion Criteria:

• History of pregestational diabetes (type 1 or type 2), history of gestational diabetes in a previous pregnancy, or diagnosis of gestational diabetes in the current pregnancy
• Multifetal gestation (twins or higher-order pregnancies)
• Currently participating in another research study involving an intervention
• Has a family member who has already been invited to participate in this study and/or shares a kitchen with such a person
• Has a serious underlying medical or psychiatric condition requiring specialized clinical care, including active cancer, severe renal or hepatic disease, symptomatic heart disease, autoimmune disorders requiring immunosuppressive therapy, active thromboembolism or coagulopathy, or severe mental health condition, or other conditions at the discretion of the investigators
• Plans to move out of the study area within the next two years

De-identified individual participant data underlying published primary and secondary analyses, including demographic, anthropometric, laboratory, and questionnaire data.

Beginning at the time of publication of the main study paper or completion of primary study data collection and cleaning, whichever comes first, with no end date.

All data will be stored and accessible through the NICHD DASH repository, following standard procedure for that repositoiry, requiring the completion of a Data Use Agreement which prohibits any redistribution or attempts to re-identify research participants.