Research & Methodology

Hall JC, Rosbash M, Young MW. Nobel Prize in Physiology or Medicine, 2017. "Discoveries of molecular mechanisms controlling the circadian rhythm."

How we use this: The foundational discovery that every cell in the body contains a molecular clock. This is the scientific basis for our entire protocol system.

Takahashi JS. Molecular components of the mammalian circadian clock. Handbook of Experimental Pharmacology. 2017;217:13-30.

How we use this: Explains the molecular machinery (CLOCK, BMAL1, PER, CRY genes) that drives circadian rhythms, informing how we model the 24-hour cycle.

Panda S. Circadian rhythms, sleep, and metabolism. Journal of Clinical Investigation. 2016;126(4):1454-1460.

How we use this: Demonstrates the connection between circadian rhythms and metabolic function, which forms the basis of our meal timing recommendations.

Roenneberg T, Wirz-Justice A, Merrow M. Life between clocks: daily temporal patterns of human chronotypes. Journal of Biological Rhythms. 2003;18(1):80-90.

How we use this: The foundational paper on chronotype assessment methodology. Our quiz is modeled on established chronotype questionnaire principles from this research.

Roenneberg T, Pilz LK, Zerbini G, Winnebeck EC. Chronotype and social jetlag: a (self-) critical review. Biology. 2019;8(3):54.

How we use this: Defines chronotypes and their impact on health. Informs how we categorize users into Lion, Bear, Wolf, and Dolphin profiles.

Jones SE, et al. Genome-wide association analyses of chronotype in 697,828 individuals. Nature Communications. 2019;10(1):343.

How we use this: Identified 351 gene loci associated with chronotype, confirming that sleep-wake preferences are genetically determined — not just habits.

Giannotti F, Cortesi F, Sebastiani T, Ottaviano S. Circadian preference, sleep and daytime behaviour in adolescence. Journal of Sleep Research. 2002;11(3):191-199.

How we use this: Research on how chronotypes shift across the lifespan, informing our age-adjusted recommendations.

Wehrens SMT, et al. Meal timing regulates the human circadian system. Current Biology. 2017;27(12):1768-1775.

How we use this: This study demonstrates that meal timing can shift peripheral circadian clocks, forming the basis for our chronotype-specific meal timing windows.

Chaix A, Manoogian ENC, Melkani GC, Panda S. Time-restricted feeding and its effects on obesity, muscle mass and heart function. Cell Metabolism. 2019;29(1):11-28.

How we use this: Provides evidence for time-restricted eating benefits, which we adapt to each chronotype's optimal eating window.

Wilkinson MJ, et al. Ten-hour time-restricted eating reduces weight, blood pressure, and atherogenic lipids in patients with metabolic syndrome. Cell Metabolism. 2020;31(1):92-104.

How we use this: Clinical trial showing metabolic benefits of time-restricted eating, supporting our protocol's eating window recommendations.

Chtourou H, Souissi N. The effect of training at a specific time of day: a review. Journal of Strength and Conditioning Research. 2012;26(7):1984-2005.

How we use this: Meta-analysis showing that exercise performance varies by time of day, informing our chronotype-specific workout window recommendations.

Youngstedt SD, Elliott JA, Kripke DF. Human circadian phase-response curves for exercise. Journal of Physiology. 2019;597(8):2253-2268.

How we use this: Maps how exercise at different times shifts circadian phase, helping us recommend optimal training windows for each chronotype.

Valdez P, Ramrez C, Garca A. Circadian rhythms in cognitive performance: implications for neuropsychological assessment. Chronobiology International. 2012;29(9):1131-1138.

How we use this: Documents how cognitive performance varies by up to 20% across the day based on chronotype, forming the basis of our "peak focus window" recommendations.

Ruben MD, et al. A database of tissue-specific rhythmically expressed human genes has potential applications in circadian medicine. Science Translational Medicine. 2018;10(458):eaat8806.

How we use this: Comprehensive atlas of circadian gene expression in human tissues, supporting our organ-specific timing recommendations.

Maury E, Ramsey KM, Bass J. Circadian rhythms and metabolic syndrome: from experimental genetics to human disease. Circulation Research. 2010;106(3):447-462.

How we use this: Links circadian disruption to metabolic disease, supporting our emphasis on consistent daily timing.

Vetter C. Circadian disruption: what do we actually mean? European Journal of Neuroscience. 2020;51(1):531-550.

How we use this: Defines and categorizes types of circadian disruption, helping us identify which disruption patterns each chronotype is most vulnerable to.

Zhang R, Lahens NF, Ballance HI, Hughes ME, Hogenesch JB. A circadian gene expression atlas in mammals: implications for biology and medicine. PNAS. 2014;111(45):16219-16224.

How we use this: Modern validation that organ-level gene expression follows circadian patterns, supporting the organ rhythm framework with molecular evidence.

Mure LS, Le HD, Benegiamo G, et al. Diurnal transcriptome atlas of a primate across major neural and peripheral tissues. Science. 2018;359(6381):eaao0318.

How we use this: Maps the time-of-day rhythms of gene expression across organs, reinforcing how each organ has its own peak window through the day.