Background

Michael completed his undergraduate degree in Biology at Wingate University, Wingate, NC. He then finished both his MSPH and PhD in Epidemilogy at the Arnold School of Pubic Health, University of South Carolina, Columbia, SC.

Teaching

In the College of Nursing, Michael has taught across graduate degree programs with foci on statistics and research methods-based courses. He primarily teaches in the PhD program teaching nursing students research methods, statistical software programming, epidemiology, and biostatistics. Michael also has created a course titled “Chronobiology in Clinical and Public Health Practice”. This course is an advanced course on how circadian biology shapes medicine and health science research.

Research

Michael is interested in the effects of circadian rhythm disruption on the human body and various health outcomes. Michael also pursues research in relation to dietary sources of inflammation, physical activity, and stress on health. Michael was instrumental in the development of the Dietary Inflammatory Index (DII) which is a research tool that can quantify the inflammatory nature of diet. The DII was invented at the University of South Caorlina.

Outcomes of interest include measures and conditions related to inflammation and metabolism. He has a particular interest in working with cancer survivors in relation to diet and circadian dysregulation. Michael also is interested in understanding stress and burnout within undergraduate nursing students and how that impacts the transitions of nursing students into the workforce. 

Dissemination

Michael has presented his research at local, regional, and national conferences including the American College of Epidemiology, the Society for Epidemiological Research, and the National Rural Health Association Annual Conference. Michael publishes in a range of high-impact journals with foci touching on chronobiology, sleep nutrition, public health, oncology research and rural health.  

Professional Service

Michael is a member of the American College of Epidemiology (ACE), the Society for Epidemiological Research, the American Public Health Association, and the Sleep Research Society. Michael is a fellow at ACE and serves on the board of directors for ACE. Michael is an editor for the journal Nutrients. He has served as a reviewer on the Lifestyle and Health Behaviors Study Section, Epidemiology and Population Health (EPH) Review Branch at the National Institutes of Health. He reviews manuscripts for several journals each year. 

Research Studies (selected)

Through his work on the DII, Michael has worked with hundreds of researchers and dozens of different studies from around the world using some of the largest datasets in the United States and in the world. There are over 1,500 publications that have used the DII and his DII-based work has been highly cited.

Michael was a multiple principle investigator (MPI) for a grant funded through the National Institute for Diabetes and Digestive and Kidney Diseases to develop an intervention based on the DII. The program was called the Inflamation Management Intervention or IMAGINE, for short. This was a three-month dietary intervention with an additional one-year follow-up. Michael has worked with a number of similarly designed dietary interventions at the University of South Carolina.

Michael has extensive experience working with the Buffalo Cariodmetabolic Occupational Police Stress (BCOPS) cohort which was a collaboration between SUNY Buffalo and the National Institute for Occupational Safety and Health (NIOSH). This valuable dataset offers opportunities for molecular and behavioral research into circadian biology among a shift-working population.

Michael conducted the SHift-working Investigation of Fasting and Timing (SHIFT) of Diet study. SHIFT was a detailed seven-day assessment of diet quality and timing among nurses. The purpose was to better capture differences in diet quality and timing between dayshift and nightshift nurses. 

Publications (selected)

Tamanna N, Wirth MD*, Moran RR, Turner-McGrievy GM, Hébert JR, Liu J. Associations of Prenatal and Postpartum Dietary Inflammatory Potential with Postpartum Sleep Quality and Duration among Pregnant Women with Overweight/Obesity. Behavioral Sleep Medicine 2026; 24(2): 177-188 (PMID: 41117257).

Farrell ET, Turner-McGrievy GM, Dawson RM, Heflin K, Wirth MD‡. SHift-working Investigation of Fasting and Timing (SHIFT) of Diet: A Cross-sectional Assessment of Nurses’ Dietary Quality, Fasting Duration, and Feasibility of Completing a -day Diet Log. Chronobiology International 2025; 42(8): 1048-1059 (PMID: 40600642). 

Yell N, Crouch E, Natafgi N, Kenison K, Wirth MD‡. Factors of Registered Nurse Vacancies in the United States. Nursing Outlook 2025; 73(4): 1-13 (PMID: 40517690). 

Jancsura MK, Wirth MD, Helsabeck NP, Mercer BM, Haas DM, Greenland P, McNeil R, Levine LD, Silver R, Yee L, Saade G, Khan SS, Chung JH, Grobman W. Inflammatory Index is Differentially Associated with Cardiometabolic Health After Pregnancy Based on Adverse Pregnancy Outcome Exposure. Journal of the American Heart Association 2024; 13(24): 1-10 (PMCID: PMC11935552).

Farrell ET, Hébert JR, Heflin K, Davis JE, Turner-McGrievy GM, Wirth MD‡. Dietary Inflammatory Index (DII) and Sleep Quality, Duration, and Timing: A Systematic Review. Sleep Medicine Reviews 2024; 77: 1-10 (PMID: 38833836)

Wirth MD, Turner-McGrievy GM, Shivappa N, Murphy EA, Hébert JR. Interaction between Meal-timing and Dietary Inflammatory Potential: Association with on Cardiometabolic Endpoints in a 3-month Prospective Analysis. Journal of Nutrition 2023; 153(12): 3555-3564 (PMCID: PMC10739766).

Wirth MD, Meyer J, Jessup A, Dawson RM. Barriers and Facilitators of Diet, Physical Activity Levels, and Sleep among Nursing Undergraduates and Early-Career Nurses: A Qualitative Descriptive Study. American Journal of Health Promotion 2023; 37(6): 821-829 (PMID: 37263962). 

Wirth MD, Fekedulegn D, Andrew ME, McLain AC, Burch JB, Davis JE, Hébert JR, Violanti J. Longitudinal and Cross-sectional Associations between the Dietary Inflammatory Index and Objectively and Subjectively Measured Sleep among Police Officers. Journal of Sleep Research2022; 31(4): 1-9 (PMCID: PMC9240102).

Wirth MD, Hébert JR, Hand GA, Youngstedt SD, Hurley TG, Shook RP, Paluch AE, James SL, Blair SN. Association between Actigraphic Sleep Metrics and Body Composition. Annals of Epidemiology 2015; 25(10): 773-778 (PMCID: PMC4567903).
Wirth MD, Burch J, Violanti J, Burchfiel C, Fekedulegn D, Andrew M, Zhang H, Miller DB, Hébert JR, Vena JE. Shiftwork duration and the awakening cortisol response among police officers. Chronobiology International 2011; 28:446-457 (PMCID: PMC3655701).