Lindsay Till Hoyt, PhD

Adolescence generally represents a time of physical fitness, however, it is also a sensitive developmental period in which social, psychological, and environmental factors may play a pivotal role (positive or negative) in establishing lifelong health trajectories. In other words, it is a period of vulnerability and opportunity.


Studying Adolescent Health: From Biology to Society

As a Robert Wood Johnson Foundation Health & Society Scholar, I have expanded my work on adolescent development by both focusing in on the underlying biology of puberty, and widening my lens to identify key social and environmental impacts on health during the pubertal years. Puberty represents a time of accelerated growth and physical change second only to infancy, during which youth experience simultaneous physiological, social, and psychological changes. Both the discrete period of change across the pubertal transition, and the timing (or initiation) of puberty, are implicated in health outcomes, and health disparities, across the lifespan. Therefore, I have focused my recent research on puberty, specifically the pubertal transition for girls, through two unique avenues.

First, I joined an interdisciplinary team of pediatricians, epidemiologists, and social scientists on the Cohort Study of Young Girls Nutrition, Environment, and Transitions (CYGNET Study), a prospective, longitudinal study of the pubertal transition that began in 2005. I am working on a number of projects with CYGNET Study PI, Larry Kushi (Kaiser Permanente), and RWJF faculty Robert Hiatt (UCSF), Julianna Deardorff (UCB), Irene Yen (UCSF), Nancy Adler (UCSF), and Barbara Laraia (UCB). For example:

  • In one project using direct observations to characterize the immediate environment around each girls’ residence, we found that girls living in neighborhoods characterized by physical disorder or high access to food and service retailers had more than twice the odds of becoming obese than their peers, across four years of follow-up (Hoyt, Kushi, Leung, Nichleach, Adler, Laraia, Hiatt, & Yen, 2014). (RWJF summary link.)
  • In a second project, we are using latent growth curve modeling to understand how pubertal timing (i.e., initiation of puberty) and tempo (i.e., rate of pubertal progression) affect sleep trajectories over eight years, from middle childhood through adolescence (Hoyt, Deardorff, Hagan, Greenspan, Windham, Harvey, Kushi, & Hiatt, in prep).
  • In 2014, I received a seed grant from the Robert Wood Johnson Foundation to collect additional data (blood samples, anthropometric measures, and survey questions) from a sub-sample of CYGNET Study participants. In this ongoing work, I am examining the impact of pubertal timing, sleep patterns, and psychosocial influences on key pre-disease pathways (e.g., inflammation).

As a second approach to understanding complex associations between puberty and health, I wrote a review and theory-building paper on reproductive transitions and their implications for women’s health in collaboration with a public health graduate student, April Falconi, who studies perimenopause. Despite growing evidence suggesting that the timing and experience of puberty and perimenopause are each associated with adult health and disease, these two processes are rarely examined together. In this paper, we bridge these disparate literatures to explore how studying these chronologically distant, yet physiologically connected, reproductive events together may help us understand important issues in women’s health (Hoyt & Falconi, 2015).

Positive Youth Development: A Period of Opportunity

Another defining aspect of my work is my adaption of the positive youth development (PYD) model to study physical health. My research on PYD shows that positive emotions, optimism, and social support during adolescence play a unique and important role in promoting healthy development (Hoyt, Chase-Lansdale, McDade, & Adam, 2012; Ehrlich, Hoyt, Sumner, McDade, & Adam, 2015; Hoyt, Craske, Mineka, & Adam, In Press). Now, as a RWJF Health & Society Scholar, I have the opportunity to apply this PYD approach in practice. I am engaged in an exploratory project with UCB faculty Emily Ozer and Allison Harvey (PIs) to pilot test a universal intervention to reduce risky health behaviors among high school students by improving sleep. This novel “Sleep Fitness” program incorporates empirically-supported clinical treatment approaches, sleep science research, and principles of participatory research. Can we promote positive youth development by improving sleep fitness in adolescence?

Based on the outdated deficit models of adolescent development, perhaps it is not surprising that most health education curricula are problem-focused. However, the PYD perspective asserts that youth can be directed to the promotion of desired outcomes, and not only to the prevention of undesirable behaviors. It is exciting to be part of a team looking for new and innovative ways to promote positive and healthy youth development.


Lindsay completed her PhD in Human Development and Social Policy at Northwestern University in 2013. She lives in San Francisco with her husband Neil, and together they love gallivanting around the lively city and exploring the beautiful Bay Area. You can follow Lindsay on Twitter @LindsayTillHoyt or read her blog posts for the Society for Research on Adolescence: