Behavioral Health & Nutrition
What are your general research interests?
My general research interest is in energy balance and the mechanisms that contribute to desirable or less desirable weight gain, growth, and nutritional status in infants and children who are healthy and in those with chronic disease. Numerous studies in both animals and humans have shown that early life nutrition can have an impact on adult diseases such as cancer, diabetes, arteriosclerosis, and obesity. This underscores the importance of early life factors for both scientific inquiry and preventive intervention.
What are your current projects and how are they funded? Who are your collaborators on these projects?
I am working on a pilot study of energy balance in infants with “normal” versus “rapid” weight gain. Numerous studies have shown that infants with rapid weight gain have a higher body mass index (BMI) and higher percent body fat at six months of age compared to their normally growing counterparts. This higher BMI and percent body fat remain into childhood and are risk factors for adult obesity. The primary aim of this project is to identify the mechanisms of energy imbalance in infants with rapid versus normal weight gain. The secondary aims are to evaluate markers of inflammation, gut peptides, and gut microbiota in these infants. This study is funded by the University of Delaware Research Foundation (UDRF). My collaborators include Sandra Hassink and Amy Renwick (Nemours/A.I. duPont Hospital for Children), Julie Mennella (Monell Chemical Senses Center), Dale Schoeller (University of Wisconsin), and Gary Wu (University of Pennsylvania).
I am also completing two projects in infants and children with chronic disease. One focuses on the energy expenditure requirements of infants with congenital heart defects post-surgical correction. The other focuses on the energy expenditure requirements of children with Down Syndrome. These studies were both funded by the National Institutes of Health (NIH). My collaborators on these projects include Virginia Stallings and Nicolas Stettler (Children’s Hospital of Philadelphia) and Barbara Medoff-Cooper and Sharon Irving (University of Pennsylvania School of Nursing).
What are the likely “next steps” in your work?
I have two proposals awaiting review. One requests funding from NIH to study the impact of diet composition during infancy on energy balance, satiety, and growth. While breast milk is considered the preferred diet in infancy and is the gold standard for infant nutrition, more than 60% of American infants receive some infant formula by four months of age. Research has shown that infants who are formula fed tend to weigh more and have a greater risk for later obesity than do infants who are breastfed. However, we recently discovered that one type of infant formula normalized weight gain of formula-fed infants relative to that of breastfed infants during the first year of life. We propose to conduct a randomized trial in which we will evaluate the effect of diet composition on growth, total and resting energy expenditure, energy intake, energy loss in stool, biomarkers of satiation and satiety (active GLP-1 and ghrelin, respectively), and later-life food preferences. My collaborators on this effort include Julie Mennella (Monell Chemical Senses Center), Virginia Stallings and Nicolas Stettler (Children’s Hospital of Philadelphia), and Dale Schoeller (University of Wisconsin).
I am also collaborating with Mia Papas from the University of Delaware Department of Behavioral Health and Nutrition. We recently submitted a proposal to the General University Research (GUR) fund to investigate the differential impact of the timing of early weight gain on the development of overweight and obesity at six years of age. We propose to compare the predictive ability of two different definitions of early rapid weight gain to determine which model better predicts overweight and obesity at six years of age. The findings from this research will have clinical relevance—the results may be used within primary care practice settings for the early identification and targeted intervention of children at high risk for obesity.
How would you describe your work’s importance to an interested lay audience?
Science indicates that there are sensitive periods during which an organism is particularly susceptible to long-term effects of various environmental influences or triggers. Since nutrition and growth in infancy are key influences, it is imperative that we understand the mechanisms by which diet composition and growth in infancy influence energy balance and later-life health outcomes.