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Introduction Much is to be learned about humanbreast milk (HBM) Purpose Extend our knowledge of HBM by investigating the role of maternal body mass index (BMI), sex and stage of lactation (month 1 vs. 6) on HBM insulin, glucose, leptin, IL-6 and TNF-α and their associations with infant body composition. Methods Thirty-seven exclusively breastfeeding infants (n=37; 16♀, 21♂) and their mothers (19–47 kg/m2) were studied at 1 and 6 months of lactation. Infants had body composition measured (using dual energy X-ray absorptiometry (DXA)) and HBM collected. Results A significant interaction between maternal BMI and infant sex on insulin levels (p = 0.0322) was observed, such that insulin was 229% higher in obese mothers nursing female infants than in normal weight mothers nursing female infants and 179% higher than obese mothers nursing male infants. For leptin, a significant association with BMI category was observed (p < 0.0001) such that overweight and obese mothers had 96.5% and 315.1% higher leptin levels than normal weight mothers, respectively. Leptin was also found to have a significant (p = 0.0004) 33.7% decrease from month 1 to month 6, controlling for BMI category and sex. A significant inverse relationship between month 1 leptin levels and infant length (p=0.0257), percent fat (p=0.0223), total fat mass (p=0.0226) and trunk fat mass (p=0.0111) at month 6 was also found. No associations or interactions were observed for glucose, TNF-α, or IL-6. Conclusions These data demonstrates that maternal BMI, infant sex and stage of lactation affect the compositional make-up of insulin and leptin.

In rural Native American communities, access to healthy foods is limited and diet-related disparities are significant. Tribally owned and operated convenience stores, small food stores that sell ready-to-eat foods and snacks primarily high in fat and sugar, serve as the primary and, in some areas, the only food stores. The Tribal Health and Resilience in Vulnerable Environments or “THRIVE” study, implemented between 2013 and 2018, is the first healthy retail intervention study implemented in tribally owned and operated convenience stores. THRIVE aims to increase vegetable and fruit intake among Native Americans living within the Chickasaw and Choctaw Nation of Oklahoma. The study comprises three phases: 1) formative research assessing tribal community food environments and associated health outcomes; 2) intervention development to assess convenience stores and tailor healthy retail product, pricing, promotion, and placement strategies; and 3) intervention implementation and evaluation. In this paper we share the participatory research process employed by our tribal-university partnership to develop this healthy retail intervention within the unique contexts of tribal convenience stores. We summarize our methods to engage tribal leaders across diverse health, government, and commerce sectors and adapt and localize intervention strategies that test the ability of tribal nations to increase fruit and vegetable purchasing and consumption among tribal members. Study processes will assist in developing a literature base for policy and environmental strategies that intervene broadly to improve Native community food environments and eliminate diet-related disparities among Native Americans.

Objectives. To assess a healthy retail intervention in Tribal convenience stores in Oklahoma. Methods. We adapted healthy retail strategies to the context of 8 Tribally owned stores. We assessed individual- and store-level outcomes in a cluster-controlled intervention trial (April 2016–June 2017). We measured fruit and vegetable intake, store environment perceptions, and purchases before and after the intervention among a cohort of 1637 Native American shoppers. We used mixed-effects linear regression to estimate pre- to postintervention changes in and between groups. Results. We followed 74% of participants (n = 1204) 9 to 12 months. Intervention and control participants perceived healthier stores after intervention. Higher shopping frequency was related to purchases of fruits, vegetables, and healthy items. Conclusions. Intervention exposure was associated with healthy purchasing but not fruit and vegetable intake. Research is needed to further assess impacts of environmental interventions on intake. Public Health Implications. As the first healthy retail intervention in Tribally owned stores, our results contribute evidence for environmental and policy interventions to address obesity in Tribal Nations. Multicomponent interventions, led by Tribal leaders from diverse sectors, are needed to create healthy environments and sustainable improvements in Native American health.