**Background:** Childhood obesity disproportionately affects ethnic minority children in immigrant families. Brazilians are a rapidly growing ethnic immigrant population in the U.S. (approximately 710,000 in 2019, with Massachusetts having the second largest population), yet no childhood obesity prevention interventions have been developed specifically for this group. Brazilians are distinct from other Latino populations, primarily speaking Portuguese and having unique cultural origins (Portuguese, African, and Indigenous). Parents play a critical role in shaping young children's energy balance-related behaviors (EBRBs), including diet, physical activity, screen time, and sleep. This formative study aimed to assess Brazilian immigrant parents' preferences for intervention content, delivery modalities, and communication technology use to inform the design of a culturally tailored family-based intervention.
**Methods:** This developmental cross-sectional pilot study recruited 52 Brazilian immigrant parents (27 mothers, 25 fathers) from Massachusetts communities between January and August 2020. Eligibility criteria included: self-identifying as Brazilian, having at least one child aged 2–5 years, being ≥21 years old, living in Massachusetts for ≥12 months, speaking Portuguese or English, and providing informed consent. Recruitment used direct strategies (in-person outreach at faith- and community-based events) and indirect strategies (flyers, social media, snowball sampling). Data were collected via a 44-item survey instrument developed based on literature review, the "5-2-1-0+10" public health guidelines, and prior qualitative research. The survey assessed: (1) preferences for informational content on seven EBRBs (5-point Likert scale); (2) preferences for 11 delivery modalities (5-point Likert scale); (3) access and use of communication technology (7 items); and (4) language preference. Acculturation was measured using the Short Acculturation Scale for Hispanics (SASH), with scores dichotomized at <2.99 (low) vs. ≥2.99 (high). Analyses used Wilcoxon rank sum, Chi-square, and Fisher's exact tests to compare mothers and fathers.
**Key Results:** All 52 participants were born in Brazil, with a mean U.S. residency of 7.6 years (SD=6.6). Approximately 93% (n=48) had low acculturation levels, and all reported Portuguese as their primary language. Regarding informational content, ≥85% of parents were interested/very interested in five of seven EBRBs: reducing unhealthy/junk foods (94%, n=49), increasing fruits and vegetables to ≥5/day (90.4%, n=47), increasing physical activity (91%, n=47), limiting screen time (88.5%, n=46), and reducing sugar-sweetened beverages (86.5%, n=45). Lower interest was reported for promoting water consumption (69.2%, n=36) and adequate sleep >10 h/night (67.3%, n=35). Significant differences between mothers and fathers emerged for reducing SSBs (88.9% of mothers vs. 56% of fathers interested/very interested, p=0.008) and increasing water intake (81.5% vs. 56%, p=0.04). For intervention modalities, the most preferred were group sessions delivered by community health workers (CHWs; 86.5%, n=45), email (84.6%, n=44), and SMS/text (80.4%, n=41). Mothers were significantly more likely than fathers to endorse group sessions by peer parents (74.1% vs. 48%, p=0.05), individual visits by CHWs (63% vs. 36%, p=0.05), and social media (33.3% vs. 8%, p=0.03). Technology access was high: 96.2% (n=50) had mobile phones for text messages, 90.4% (n=47) used WhatsApp, and 85.2% (n=39) checked WhatsApp daily. However, only 25% (n=13) checked email daily. Mothers were significantly more likely than fathers to use WhatsApp (100% vs. 80%, p=0.02), check messages daily (85.2% vs. 56%, p=0.003), check email daily (37% vs. 12%, p=0.04), and have a home computer (77.8% vs. 48%, p=0.03). Most parents (71.2%, n=37) preferred Portuguese-language content, with no significant difference between mothers (70.4%) and fathers (72%).
**Clinical Implications:** This formative research provides the first evidence to guide development of family-based obesity prevention interventions for Brazilian immigrant families in the U.S. The high interest in most EBRB content areas suggests parents are receptive to intervention, though the lower interest in water consumption and sleep indicates these topics may require additional health education. The strong preference for CHW-delivered group sessions aligns with Brazil's established community health worker model ("Agentes Comunitários de Saúde") and prior successful Latino interventions (e.g., ANDALE Pittsburgh, Aventuras Para Niños). The discrepancy between email preference (84.6%) and actual daily email checking (25%) versus near-universal daily WhatsApp checking (>90%) suggests that mHealth approaches using WhatsApp and SMS/text may be more effective delivery channels than email. The strong preference for Portuguese-language content (71.2%) underscores the need for linguistic tailoring. The significant differences between mothers and fathers in content preferences and modality preferences highlight the importance of designing interventions that engage both parents. Limitations include the small convenience sample (n=52) from Massachusetts with low acculturation levels, limiting generalizability. Future research should include larger, more diverse samples and pilot test multi-component interventions integrating CHW-led group sessions with mHealth components (SMS/text and WhatsApp) and printed materials.