How a USC doctoral candidate is exploring sleep’s impact on childhood obesity


Department of Population and Public Health Sciences

Publish date

April 3, 2019


This post is part of our National Public Health Week series! We’re putting the spotlight a different area of public health each day. We hope you are as inspired as we are by the featured change-makers in this series.

Sydney O'Connor, BA

Pictured: Sydney O’Connor.
Photo courtesy Sydney O’Connor

What area of public health does your research focus on?

My research seeks to understand the etiology of health behaviors related to obesity and other chronic diseases. To do so, I use Ecological Momentary Assessment (EMA) – an approach used to repeatedly assess and measure individuals’ behaviors, psychological states and social and environmental contexts in real-time within their naturalistic settings. I’m particularly interested in using novel methods (such as smartphone apps and sensors) to measure and understand the factors that influence sleep, dietary quality and eating behaviors among children and families. My doctoral dissertation explores the role of night-to-night variability in sleep health on children’s dietary quality, eating behavior, and longitudinal obesity risk. This project is supported by an individual training grant from the National Heart, Lung, and Blood Institute, part of the National Institute of Health (F31HL137346).

What drew you to this issue in particular?

Growing evidence from cross-sectional and longitudinal studies suggests that children with habitually short sleep have nearly double the risk of overweight and obesity compared to children with the longest sleep. However, many previous studies have had methodological limitations. For example, studies have used retrospective report of sleep (asking children to recall their average sleep over the past month), which can be prone to recall bias. Furthermore, it’s still unknown exactly what mechanisms or pathways might link short sleep or other sleep characteristics (such as high night-to-night variability in bedtime across nights) to weight gain. The rising popularity of smartphones and wearable sensors provides a unique opportunity for behavioral health research. Leveraging these technologies, we can capture detailed information on these high-occurrence health behaviors, allowing us to understand the external and internal factors that may impact behaviors over time. This may lead to new insights on everyday behaviors, with the potential to inform more targeted, effective interventions.

What are your research goals?

We know that diet and activity are the two most important behavioral predictors of obesity, but many of the interventions that have been designed to address these behaviors have had only modest success. Sleep is another modifiable behavior with the ability to affect weight status, however, there are still a number of unanswered questions. My goal is to understand the role of sleep on eating patterns and obesity risk by addressing three questions: (1) How does a novel EMA daily method of sleep assessment compare to other established methods (such as activity monitors), and can it be used in future studies as a low-burden and low-cost alternative?; (2) How does a night of poorer-than-usual sleep affect children’s next-day dietary quality and eating behavior?; and (3) What is the longitudinal association of short and highly variable sleep duration on children’s long-term obesity risk?

What does your research entail?

I am fortunate to be a member of a wonderful research team – the USC Real Time Eating Activity & Children’s Health (REACH) Lab, led by Dr. Genevieve Dunton, who is also my doctoral mentor. Our team consists of high school students, undergraduate and master’s degree students, pre- and post-doctoral fellows, staff and several other faculty members. One of my favorite parts of being a behavioral health researcher is the balance of working both collaboratively and independently to achieve goals. Our lab regularly meets to collaborate on projects and provide feedback and mentorship to each other on our ongoing work. Academic conferences also provide great opportunities to network and build collaborations. However, the majority of my day-to-day work is spent working independently to analyze data and write up the results for publication in academic journals. More recently, I have seen a big push among researchers to become more engaged in disseminating their findings to the public through social media platforms including Twitter. I think this is an important step for engaging with other researchers and the general public, and for translating research findings into public health improvements.

Environmental Health Assembly Student Mentee Science Fair Judge

Pictured: Sydney O’Connor
Photo courtesy Sydney O’Connor

Why is it so important to understand obesity in children?

A substantial and growing proportion of the U.S. population is overweight or obese, putting them at heightened risk of cardiovascular disease, diabetes and certain cancers. Currently, one in every three children is classified as overweight or obese. It’s of the utmost importance to halt the increasing prevalence of childhood obesity, especially due to children’s increased vulnerability. We know that weight-promoting behaviors (overeating, avoiding vegetables, too much sedentary screen time) that are learned in childhood tend to persist into adulthood. Children who become overweight or obese are significantly more likely to remain overweight as adults. Finally, it has been demonstrated that obesity has strong inter-generational effects, which has serious implications for the health and well-being of future generations.

What are the major challenges surrounding the study of obesity?

While behaviors are an important (and modifiable) component of the obesity epidemic, it is important to emphasize that obesity is not simply an individual-level problem. Instead, the steady increase in obesity prevalence over the past several decades suggests that external factors play a large role in promoting weight gain. There are a whole host of factors that have contributed to the dramatic rise in obesity over the past several decades, including individual (beliefs, biology, and behavior), social (peer influences), environmental (availability of fruits/vegetables and green space), and societal-level factors (culture of convenience, affordability, advertisements). These factors also influence the disparate burden experienced by communities of color and low-income communities, in which rates of obesity and other chronic diseases are even higher. Addressing this epidemic cannot wait; individuals, families, organizations, communities and policy makers must work together to address the many factors contributing to childhood obesity.

Population and Public Health Sciences students

Pictured: Population and Public Health Sciences students.
Photo courtesy Sydney O’Connor

What can the public do?

Become familiar with behavioral recommendations for health. The Society of Behavioral Medicine – Healthy Living resource is a good start. Practice sleep hygiene. Strive to fill half of your plate with fruits and vegetables – the more colorful the better. Limit (or remove entirely!) red/processed meat, refined grains and highly processed packaged foods such as soda, chips, and candy/sweets from your diet. Strive to be physically active every day and limit the amount of time you spend in front of a screen.

Conference- Society of Behavioral Medicine

Pictured: Sydney O’Connor at Society of Behavioral Medicine conference.
Photo courtesy Sydney O’Connor

Where can people go to learn more?

In this age of information, it’s easy to feel overwhelmed by the many competing interests claiming to know the “best” or “healthiest” new tips. When encountering new health-related information, consider the source (is it trustworthy?) and the motive (is it an advertisement?), and the accuracy (are sources cited?). Health and fitness trends come and go, but the evidence-based foundations of healthy living do not change overnight.




Recommended resources:

Find O’Connor on Twitter:

Interested in health behavior research? Our Doctorate in Health Behavior Research provides students with the skills and knowledge they need to make a difference. Download our Degrees and Careers Guide to read more about our education offerings and the field of public health.

Featured image: The REACH Lab. Photo courtesy Sydney O’Connor

Related News