Professional Education

  • Doctor of Philosophy, Arizona State University, Exercise and Nutritional Sciences (2023)
  • Master of Science in Education, Western Oregon University, Health (2017)
  • Bachelor of Science, Western Oregon University, Exercise Science (2015)

Stanford Advisors

Current Research and Scholarly Interests

Dr. Royer's research interests include food insecurity, eating behaviors, and physical activity. His research primarily aims to remove barriers hindering individuals from accessing healthy food. Dr. Royer seeks to advance public health by sustainably promoting healthy eating and food security through innovative and evidence-based research approaches. Through his research, he is motivated to promote food security, healthy eating, and physical activity toward the prevention of chronic disease.

All Publications

  • The Folly of Food Waste amidst Food Insecurity in the United States: A Literature Review CHALLENGES Royer, M. F. 2024; 15 (2): 1-17

    View details for DOI 10.3390/challe15020021

  • The Design and Testing of a Text Message for Use as an Informational Nudge in a Novel Food Insecurity Intervention CHALLENGES Royer, M. F., Wharton, C. 2023; 14 (4): 1-13

    View details for DOI 10.3390/challe14040040

  • Absent mindfulness: mediation analyses of the relationship between adverse childhood experiences and disordered eating among young adults FRONTIERS IN CHILD AND ADOLESCENT PSYCHIATRY Royer, M. F., Cosgrove, K., Wharton, C. 2023; 2: 1-12
  • The FINDING-Food Intervention: A Mixed-Methods Feasibility Study Addressing Food Insecurity. CHALLENGES Royer, M. F., Wharton, C. 2023; 14 (4): 1-18

    View details for DOI 10.3390/challe14040043

  • Association between household food insecurity during the COVID-19 pandemic and subjective cognitive difficulties among adolescents in the United States PSYCHIATRY RESEARCH Onyeaka, H. K., Baiden, P., Royer, M. F., Muoghalu, C., LaBrenz, C. A., Nicholas, J. K., Spoor, S., Bock, E., Adeku, Y. 2022; 318: 114936
  • Physical activity mitigates the link between adverse childhood experiences and depression among US adults PLOS ONE Royer, M. F., Wharton, C. 2022; 17 (10): e0275185


    Adverse Childhood Experiences (ACEs) include potentially traumatic exposures to neglect, abuse, and household problems involving substance abuse, mental illness, divorce, incarceration, and death. Past study findings suggest ACEs contribute to depression, while physical activity alleviates depression. Little is known about the link between ACEs and physical activity as it relates to depression among U.S. adults. This research had a primary objective of determining the role of physical activity within the link between ACEs and depression. The significance of this study involves examining physical activity as a form of behavioral medicine.Data from the 2020 Behavioral Risk Factor Surveillance System were fit to Pearson chi-square and multivariable logistic regression models to examine the links between ACEs and depression, ACEs and physical activity, and physical activity and depression among U.S. adults ages 18-and-older (n = 117,204) from 21 states and the District of Columbia, while also determining whether physical activity attenuates the association between ACEs and depression.Findings from chi-square analyses indicated that ACEs are related to physical activity (χ2 = 19.4, df = 1; p<0.01) and depression (χ2 = 6,841.6, df = 1; p<0.0001). Regression findings suggest ACEs were linked to depression (AOR = 1.050; 95% CI = 1.049, 1.051). ACEs and physical activity (AOR = 0.994; 95% CI = 0.992, 0.995) and physical activity and depression (AOR = 0.927; 95% CI = 0.922, 0.932) were both inversely related. Physical activity mitigated the link between ACEs and depression (AOR = 0.995; 95% CI = 0.993, 0.996).This research addressed a critical knowledge gap concerning how ACEs and physical activity contribute to depression outcomes among U.S. adults. Findings suggest physical activity mitigates the effect of ACEs on depression. Future studies should apply physical activity interventions to alleviate depression among U.S. adults with high ACEs.

    View details for DOI 10.1371/journal.pone.0275185

    View details for Web of Science ID 000891284400022

    View details for PubMedID 36223342

    View details for PubMedCentralID PMC9555628

  • Food insecurity and adverse childhood experiences: a systematic review NUTRITION REVIEWS Royer, M. F., Ojinnaka, C. O., Zhang, X., Thornton, A. G., Blackhorse, K., Bruening, M. 2022; 80 (10): 2089-2099


    Food insecurity (FI) and adverse childhood experiences (ACEs) disproportionally affect vulnerable populations and are key social determinants of health that predict nutrition-related outcomes. It is critical to understand how FI and ACEs are interrelated so prevention studies can be designed to better promote health equity.A systematic literature review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to determine the association between FI and ACEs.Google Scholar, PubMed, and Scopus databases were used to find articles relevant to the study. Inclusion criteria included quantitative, qualitative, or mixed-methods studies of humans, using an experimental or observational research design to examine the relationship between FI and ACEs using the validated ACEs measure in its entirety.Studies were assessed for study design, data set, population descriptions, and results of the association between FI and ACEs. Additionally, all included studies were assessed for bias and validity.A total of 10 articles were included in the systematic review. Of those articles, 9 were reports on cross-sectional studies, and 1 reported on a longitudinal study; however, all 10 studies used a retrospective approach. Six studies were conducted using secondary data. Results reported in all 10 articles indicated a significant positive association between FI and ACEs. Evidence indicated greater odds of FI among individuals with high ACE scores, with most studies indicating a dose-response or a threshold effect of higher ACEs being associated with more severe FI.FI and ACEs are consistently related. Prevention study interventions should be designed to address FI and problems stemming from ACEs. Filling knowledge gaps regarding the relationship between ACEs and FI is critical for designing nutrition interventions that promote food security, prevent the occurrence of ACEs, and improve health outcomes among vulnerable populations with high ACEs.PROSPERO registration no.: CRD42020210106.

    View details for DOI 10.1093/nutrit/nuac029

    View details for Web of Science ID 000792555000001

    View details for PubMedID 35535026

  • Availability, variety and distribution of healthy and unhealthy foods and beverages sold at street food stands in Mexico City PUBLIC HEALTH NUTRITION Chavez, J., Bruening, M., Royer, M. F., Ohri-Vachaspati, P., Lee, R. E., Jehn, M. 2021; 24 (17): 5577-5588


    To examine differences in the availability, variety and distribution of foods and beverages sold at street food stands (SFS) across neighbourhood income levels in Mexico City.Cross-sectional.Twenty neighbourhoods representing low-, middle- and high-income levels in Mexico City.Direct observations of SFS (n 391).The availability of healthy foods such as fruits/vegetables was high in middle- and high-income neighbourhoods, whereas the availability of unhealthy foods such as processed snacks was higher in low-income neighbourhoods. However, statistically significant differences in food availability across neighbourhoods were only observed for dairy and processed snack items (P < 0·05). Similarly, differences in variety were only observed for cereal and processed snacks (P < 0·05). No statistically significant differences were seen for variety of fruits/vegetable across neighbourhood income levels (P > 0·05). No statistically significant differences across neighbourhood income levels were observed for beverage availability and variety (P > 0·05). Although street foods and beverages were often distributed near homes, public transportation centres and worksites, no differences were observed across neighbourhood income levels (P > 0·05).Findings suggest that SFS can be a source of both unhealthy foods and healthy foods for communities across neighbourhoods in Mexico City. Additional studies are needed to assess the relationship between street food and beverage availability, and consumption.

    View details for DOI 10.1017/S136898002100330X

    View details for Web of Science ID 000720784600003

    View details for PubMedID 34369345

    View details for PubMedCentralID PMC8609361

  • Food Insecurity is Related to Disordered Eating Behaviors Among College Students JOURNAL OF NUTRITION EDUCATION AND BEHAVIOR Royer, M. F., Ojinnaka, C. O., Bruening, M. 2021; 53 (11): 951-956


    To determine the association between food insecurity and disordered eating behaviors (DEBs) in undergraduate college students.Cross-sectional data of college students (n = 533) were collected from February to April 2020. Food security was measured with the US Department of Agriculture's Adult Food Security Survey Module. Disordered eating behaviors were measured with the Eating Disorder Examination Questionnaire. Associations were examined statistically with Pearson chi-square tests of independence and general linear regression models.Across all food security ranges, linear trends detailed significant associations between food insecurity and global DEBs (β = 0.17; P < 0.001), eating concern (β = 0.27; P < 0.001), shape concern (β = 0.17; P = 0.001), and weight concern (β = 0.21; P < 0.001), but not restraint (β = 0.10; P = 0.08).Food insecurity was consistently related to DEBs. Future research may consider longitudinally examining this relationship, as food insecurity and DEBs may be associated with worse health outcomes among vulnerable college students.

    View details for DOI 10.1016/j.jneb.2021.08.005

    View details for Web of Science ID 000751648300008

    View details for PubMedID 34561153

  • Food Insecurity Is Associated with Cognitive Function: A Systematic Review of Findings across the Life Course INTERNATIONAL JOURNAL OF TRANSLATIONAL MEDICINE Royer, M. F., Guerithault, N., Braden, B. B., Laska, M. N., Bruening, M. 2021; 1 (3): 205-222

    View details for DOI 10.3390/ijtm1030015