Cooperative Extension Specialist
About Susana Matias
Dr. Matias is a Cooperative Extension Specialist in the Department of Nutritional Sciences and Toxicology (NST) at the University of California, Berkeley. She has 10+ years of experience in public health nutrition and a training profile that blends nutrition, epidemiology and psychology. Her research focuses on food access and its connection with dietary patterns and health. She studies maternal and child nutrition, immigrant health, food security, and obesity and diabetes prevention through nutritional and behavior change. Prior to joining NST, Dr. Matias was an Assistant Project Scientist in the Department of Nutrition at the University of California, Davis.
My research centers in topics that a) promote health through nutrition and b) prevent nutrition related conditions, with a focus in disadvantaged populations.
Breastfeeding has many benefits, for both infants and women. However, some mother-child dyads experience difficulties establishing breastfeeding, which can increase the risk of early breastfeeding discontinuation. Understanding the risk factors for early breastfeeding problems could assist targeting efforts to provide extra lactation support early on. We studied the prevalence of early lactation problems (i.e. delayed lactogenesis, excessive newborn weight loss, sub-optimal breastfeeding behavior), and their association with later optimal breastfeeding practices (i.e. exclusive breastfeeding) in a low-income community in Lima, Peru. We found less early breastfeeding problems in this setting, compared to the US, which may relate to the differences in childbirth practices between these two countries. Interestingly, early lactation problems were not associated with early discontinuation of exclusive breastfeeding, as has been observed in the US. This finding highlights the importance of cultural and environmental support towards breastfeeding.
In Northern California, we investigated the risk factors for delayed lactogenesis (i.e. arrival of breastmilk after 72 h postpartum) among women with a gestational diabetes mellitus (GDM) diagnostic. In this population, obesity, severity of GDM and suboptimal breastfeeding performance were risk factors for delayed lactogenesis. Because information on these potentially modifiable risk factors is generally available in clinical settings, these findings are useful for screening GDM women at higher risk of delayed lactogenesis, and consequently at higher risk of early breastfeeding discontinuation.
Latinos experience higher rates of obesity than Whites do, with even higher rates in rural areas. Rural populations face unique environmental conditions because of its isolated location, the limited infrastructure and resources available. Using data from a cohort of Latino farm workers in the California Central Valley, we assessed the association between acculturation and dietary patterns in this population. Despite their low acculturation levels, several acculturation indicators were associated with fruit/vegetable consumption and fat intake, all except one in the anticipated direction (i.e., low acculturation -> healthier dietary patterns). Thus, acculturation is an important factor to consider when designing culturally tailored interventions in this immigrant farm worker population. Another interesting finding was the association between school attendance in the US and having a child at home with higher fat intake in this adult population. These findings could inform nutrition education interventions for Latino farm workers.
Next, we moved from understanding the Latino population dietary practices to promoting behavioral change. In an unprecedented partnership with a berry producer in California, we implemented a randomized pilot intervention targeting Latino farm workers in the areas of Oxnard and Watsonville. This intervention aimed to reduce obesity and prevent diabetes and was implemented in collaboration with the farm workers’ employer organization. In addition to nutritional education this pilot intervention promoted physical activity. This intervention resulted in increased consumption of water, fruits and vegetables and the time spent in moderate physical activity in the overall sample, and reduced weight, body mass index and waist circumference among females.
My research program also includes impact and process evaluation research. In particular, I evaluated the effectiveness of a novel nutritional product, lipid-based nutrient supplements (LNS). LNS products provide key macronutrients, including essential fatty acids, and several micronutrients in amounts appropriate for the needs of specific population groups (women and infants) and are added to a regular meal as they are considered home fortification products. This product is a promising alternative to prevent stunting and potentially anemia in low-income settings.
We conducted two randomized effectiveness trials to evaluate the effectiveness of LNS on reducing stunting and anemia and improving child development: 1) a longitudinal, cluster- randomized trial with four arms involving women and children in Bangladesh (n=4,011), and 2) a randomized trial with two arms allocating infants (n=422) to receive either LNS or the standard of care in Peru. Because LNS was a novel approach and not produced locally, we also conducted a process evaluation and a cost analysis study. This information is needed for advancing public health decisions and policy.
Both of these LNS interventions were added into existing programs, thus the implementation of these trials relied on successful partnerships beyond academia. In Bangladesh, we collaborated with a non-profit organization already implementing a community-based program in the study area. In Peru, collaboration between academia, a humanitarian non-profit organization and the government sector was fundamental for implementing the trial using the platform of a national program delivered in health centers targeting infants and young children. These types of collaborations beyond academia are critical for conducting community-based interventions and testing the feasibility of scaling up successful nutrition interventions.
- Ph.D., Epidemiology, with Designated Emphasis in International and Community Nutrition, University of California, Davis.
- M.A., Educational Psychology, Pontifica Universidad Católica del Perú
- B.A., Psychology, Pontifica Universidad Católica del Perú
Susana L Matias, Michelle Pearl, Kristen Lyall, Lisa A Croen, Tanja VE Kral, Daniele Fallin, Li-Ching Lee, Chyrise B Bradley, Laura A Schieve, Gayle C Windham. Maternal pre-pregnancy weight and gestational weight gain in association with autism and developmental disorders in offspring. Obesity (Silver Spring). 2021;29(9):1554-1564. https://doi.org/10.1002/oby.23228
Susana L Matias, Jazmin Rodriguez-Jordan, Mikelle McCoin. Integrated Nutrition and Culinary Education in Response to Food Insecurity in a Public University. Nutrients 2021;13(7):2304. https://doi.org/10.3390/nu13072304
Susana L Matias, Jazmin Rodriguez-Jordan, Mikelle McCoin. Evaluation of a college-level nutrition course with a teaching kitchen lab. Journal of Nutrition Education and Behavior 2021;53(9):787-792. https://doi.org/10.1016/j.jneb.2021.02.004
Kathryn Dewey, Susana Matias, Malay Mridha, Charles Arnold. Nutrient supplementation during the first 1000 days and growth of infants born to pregnant adolescents. Annals of the New York Academy of Sciences 2020;1468(1):25-34. https://doi.org/10.1111/nyas.14191
Gilberto Kac, Charles D. Arnold, Susana L. Matias, Malay K. Mridha, Kathryn G. Dewey. Gestational weight gain and newborn anthropometric outcomes in rural Bangladesh. Maternal and Child Nutrition 2019;15(4):e12816. https://onlinelibrary.wiley.com/doi/epdf/10.1111/mcn.12816
Susana L Matias, Malay K Mridha, Rebecca T Young, Sohrab Hussain, Kathryn G Dewey. Daily Maternal Lipid-Based Nutrient Supplementation with 20 mg Iron, Compared with Iron and Folic Acid with 60 mg Iron, Resulted in Lower Iron Status in Late Pregnancy but Not at 6 Months Postpartum in Either the Mothers or Their Infants in Bangladesh. Journal of Nutrition 2018;148(10):1615-1624. doi:10.1093/jn/nxy161.
Susana L Matias, Malay K Mridha, Rebecca T Young, Md. Showkat A Khan, Zakia Siddiqui, Md. Barkat Ullah, Stephen A Vosti, and Kathryn G Dewey. Prenatal and postnatal supplementation with lipid-based nutrient supplements reduces anemia and iron deficiency in 18-month-old Bangladeshi children: a cluster-randomized effectiveness trial. Journal of Nutrition 2018;148(7):1167-1176. doi: 10.1093/jn/nxy078.
Malay K. Mridha, Susana L Matias, Charles D Arnold, Kathryn G Dewey. Factors associated with nutritional status and dietary practices of Bangladeshi adolescents in early pregnancy. Annals of the New York Academy of Sciences 2018. doi: 10.1111/nyas.13568. [Epub ahead of print]
Katherine P Adams, Emmanuel Ayifah, Thokozani E Phiri, Malay K Mridha, Seth Adu-Afarwuah, Mary Arimond, Charles D Arnold, Joseph Cummins, Sohrab Hussain, Chiza Kumwenda, Susana L Matias, Ulla Ashorn, Anna Lartey, Kenneth M Maleta, Stephen A Vosti, Kathryn G Dewey. Maternal and Child Supplementation with Lipid-Based Nutrient Supplements, but Not Child Supplementation Alone, Decreases Self-Reported Household Food Insecurity in Some Settings. Journal of Nutrition 2017;147(12):2309-2318. doi: 10.3945/jn.117.257386.
Susana L Matias, Alejandro Vargas-Vásquez, Ricardo Bado Pérez, Lorena Alcázar Valdivia, Oscar Aquino Vivanco, Amelia Rodriguez Martín, Jose Pedro Novalbos Ruiz. Effects of lipid-based nutrient supplements versus micronutrient powders on nutritional and developmental outcomes among Peruvian infants. Public Health Nutrition 2017;20(16):2998-3007. doi: 10.1017/S1368980017001811.
Susana L Matias, Malay K Mridha, Fahmida Tofail, Charles D Arnold, Md Showkat Ali Khan, Zakia Siddiqui, Md Barkat Ullah, Kathryn G Dewey. Home fortification during the first 1,000 days improves child development in Bangladesh: a cluster-randomized effectiveness trial. American Journal of Clinical Nutrition 2017;105(4):958-969.
Kassandra L. Harding, Susana L. Matias, Malay K. Mridha, Md. Moniruzzaman, Stephen A. Vosti, Sohrab Hussain, Kathryn G. Dewey, Christine P. Stewart. Adherence to recommendations on lipid-based nutrient supplement and iron and folic acid tablet consumption among pregnant and lactating women participating in a community health programme in northwest Bangladesh. Maternal and Child Nutrition 2017;13(1). doi:10.1111/mcn.12252.
Susana L Matias, Malay K Mridha, Rina R Paul, Sohrab Hussain, Stephen A Vosti, Charles D Arnold, Kathryn G Dewey. Prenatal lipid-based nutrient supplements affected maternal anthropometric indicators only in certain subgroups of rural Bangladeshi women. Journal of Nutrition 2016;146: 1775-82.
Susana L. Matias, Kathryn G. Dewey, Charles P. Quesenberry, Jr., Erica P. Gunderson. Maternal pre-pregnancy obesity and insulin treatment during pregnancy are independently associated with delayed lactogenesis among women with recent gestational diabetes mellitus. American Journal of Clinical Nutrition 2014;99: 115-121.
Susana L. Matias, Maria T. Stoecklin-Marois, Daniel J. Tancredi, Marc B. Schenker. Adherence to diet recommendations is associated with acculturation among Latino farm workers. Journal of Nutrition 2013;143: 1451–1458.
Susana L. Matias, Laurie A. Nommsen-Rivers, Kathryn G. Dewey. Determinants of Exclusive Breastfeeding in a Cohort of Primiparous Peri-urban Peruvian Mothers. Journal of Human Lactation 2012;28 (1): 45-54.
Susana L. Matias, Laurie A. Nommsen-Rivers, Hilary Creed-Kanashiro, Kathryn G. Dewey. Risk Factors for Early Lactation Problems among Peruvian Primiparous Mothers. Maternal and Child Nutrition 2010;6:120-133.