The Science of Starting Over: Winter as Medicine

January feels like a chance for something new. Many people see this as a time to push harder and fix what’s wrong. But our bodies see January differently. Instead of going for big changes, this season is about resting, repairing, and restoring balance. That “fresh start” feeling that many people experience at the beginning of the year is not imagined—it’s rooted in neuroscience, biology, and seasonal physiology. When we align our actions with the season, change becomes more effortless and more lasting.

The Neuroscience of a Fresh Start

The idea of “starting over” has been extensively studied in behavioral science. Researchers describe this phenomenon as the fresh start effect—a psychological boost in motivation that occurs at certain milestones such as New Year’s Day, birthdays, or even Mondays. These time markers help the brain create a psychological separation between a “past self” and a “future self,” making change feel more attainable.¹

Neurobiologically, novelty activates brain pathways that use dopamine, a chemical messenger. Dopamine is not just a “reward” chemical as it’s often described; it mainly drives anticipation and motivation. When we set intentions and find meaning, dopamine is released, which increases focus and engagement.² However, dopamine alone does not produce lasting change. Sustainable behavior change requires regulation—the process of keeping body systems, such as the nervous system, daily body rhythms, blood sugar management, and inflammation, within healthy ranges. These are a part of what is known as winter biology.

Winter Biology as a Season of Conservation and Repair

Human physiology evolved to handle different seasons. Shorter daylight hours, colder temperatures, and reduced food availability historically signaled a time for energy conservation, immune vigilance, and tissue repair rather than maximal output.³ Even though modern life is different, our bodies still respond to these seasonal signals.

Key winter physiological shifts include:

• Increased melatonin secretion due to reduced daylight exposure⁴
• Altered cortisol patterns, often with lower morning peaks and flatter diurnal curves⁵
• Changes in glucose tolerance and insulin sensitivity⁶
• Greater immune system activity and inflammatory responsiveness⁷

These changes explain why many people often feel tired, have low motivation, more frequent infections, and increased cravings for carbohydrates in January. These are signs that the body is prioritizing repair and protection.

Circadian Rhythm is the Foundation of Winter Health

Circadian rhythm is the body’s internal 24-hour clock that controls sleep, hormone release, metabolism, immune function, and energy levels by responding to light and darkness. Disruption of this timing system is often overlooked as a contributor to today’s health problems. In winter, less light in the morning and too much artificial light in the evening can disturb the signals that maintain a healthy circadian rhythm.⁸

This disruption impacts:

• Insulin sensitivity
• Thyroid hormone conversion
• Immune regulation
• Mood and cognitive performance

Studies show that maintaining a consistent sleep schedule, even more than sleep duration, is associated with improved metabolic health and reduced inflammation.⁹ January is an ideal time to restore circadian consistency. Winter-aligned strategies include:

1. Morning light exposure within 30–60 minutes of waking
2. Earlier meal timing
3. Reduced evening blue light exposure (device screens, LED lighting)
4. Consistent sleep schedules—even on weekends

These interventions help maintain nervous system and metabolic balance more effectively than extreme diets or detoxes.

January: A Time for Metabolic & Nervous System Repair

January is often marketed as a time for diets, aggressive caloric restriction, intense exercise, and rapid weight loss. Yet research consistently shows that severe caloric restriction increases cortisol, worsens insulin resistance, and reduces resting metabolic rate—especially in already-stressed individuals.¹⁰ However, winter is an ideal season for metabolic repair, which includes:

• Stabilizing blood glucose
• Building lean muscle
• Repleting micronutrient deficiencies
• Reducing chronic inflammation

Repair happens when the body feels safe—not when it senses threat. Actual change is not created by discipline but by nervous system safety. The autonomic nervous system, which controls automatic body functions like heart rate and digestion, can stay in a sympathetic (fight-or-flight) state if you are stressed. In this mode, the body focuses more on survival than on growth or rest.11 Winter naturally encourages parasympathetic dominance, such as slower mornings, earlier evenings, quieter routines. Ways to support winter healing include:

• Gentle movement (walking, mobility, yoga)
• Breathing exercises
• Social connection
• Self-compassion (lowers cortisol and inflammatory markers¹²)

Erase New Year’s Resolutions and Support Balance

Most January resolutions fail by February. This is when the excitement wears off, motivation drops, and our bodies push back against unsustainable demands. Instead of viewing this as a failure, understand that it’s a biological correction. Studies show that habits rooted in identity, rhythm, and environmental support are far more durable than those driven by willpower.¹³ Winter offers the perfect conditions to build these foundations.

Instead of asking, “What should I change?”, January invites a different question:

“What does my body need to repair right now?”

Starting over does not mean becoming someone new or reinventing ourselves. It means returning to balance by:

• Restoring rhythm
• Lowering inflammation
• Rebuilding reserves
• Creating safety in the nervous system

When repair comes first, change follows naturally and lasts longer. Spring brings growth. Summer brings energy. But winter—quiet and thoughtful—is when healing happens.

References

1. Dai H, Milkman KL, Riis J. The fresh start effect: Temporal landmarks motivate aspirational behavior. Manage Sci. 2014;60(10):2563-2582.
2. Volkow RD, Wise RA, Baler R. The dopamine motive system: implications for drug and food addiction. Nature Reviews Neuroscience. 2017;18(12):741–752.
3. Stevenson TJ, Prendergast BJ. Reversible DNA methylation regulates seasonal photoperiodic time measurement. Proc Natl Acad Sci U S A. 2013;110(41):16651-16656.
4. Wucher V, Sodaei R, Amador R, et al. Day-night and seasonal variation of human gene expression across tissues. PLoS Biol. 2023;21(2):e3001986.
5. Adam EK, et al. Diurnal cortisol slopes and mental and physical health outcomes. Psychoneuroendocrinology. 2017;83:25-41.
6. Qian J, Scheer FAJL. Circadian system and glucose metabolism. Diabetes Care. 2016;39(5):724-733.
7. Dopico XC, et al. Widespread seasonal gene expression reveals annual differences in human immunity. Nat Commun. 2015;6:7000.
8. Wright KP Jr, et al. Entrainment of the human circadian clock to the natural light-dark cycle. Curr Biol. 2013;23(16):1554-1558.
9. Huang T, et al. Consistent sleep patterns are associated with metabolic health. Diabetologia. 2020;63(5):971-984.
10. Tomiyama AJ, et al. Low calorie dieting increases cortisol. Psychosom Med. 2010;72(4):357-364.
11. Porges SW. The polyvagal theory: New insights into adaptive reactions of the autonomic nervous system. Cleve Clin J Med. 2009;76(Suppl 2):S86-S90.
12. Breines JG, et al. Self-compassion and physiological stress responses. Psychol Sci. 2014;25(3):780-789.
13. Lally P, et al. How are habits formed: Modelling habit formation in the real world. Eur J Soc Psychol. 2010;40(6):998-1009.