A Functional Medicine Perspective on Resetting the Body for the New Year

The start of a new year naturally sparks a desire to reset — physically, mentally, and metabolically. One practice that continues to gain attention in both functional medicine and performance circles is fasting. Not as a fad. Not as punishment. But as a strategic tool to support cellular health, metabolic flexibility, and inflammation control.

From intermittent fasting windows to extended fasts, fasting has been studied for its effects on autophagy, insulin regulation, inflammation, and hormonal balance — all key drivers of long-term health and athletic performance.

Let’s break it down.

What Happens in the Body When You Fast

When you stop eating, your body doesn’t shut down — it switches gears.

Within hours of fasting:

• Insulin levels begin to drop
• The body shifts from burning glucose to burning stored fat
• Inflammatory signaling may decrease
• Hormones like growth hormone increase

This metabolic shift is foundational to why fasting has become a powerful topic in longevity and performance science.

Research Note
Lower insulin and increased fat oxidation during fasting are well-documented in human metabolic studies. Growth hormone increases during fasting have also been observed, particularly during longer fasting periods.

Autophagy: The Cellular Cleanup Crew

One of fasting’s most talked-about benefits is autophagy — the body’s built-in recycling system.

Autophagy helps:

• Break down damaged proteins
• Remove dysfunctional cellular components
• Support cellular renewal and resilience

Think of it as cellular housekeeping. When nutrients are constantly available, the body prioritizes growth. When nutrients are temporarily removed, the body shifts toward repair and efficiency.

Research Note
Autophagy occurs at baseline in all humans and increases during fasting. Most direct evidence comes from animal models, with growing but still limited human data. The exact timing of peak autophagy in humans is not precisely defined and varies by individual.

Fasting Windows: What the Research Suggests

Different fasting durations create different physiological responses. These are educational frameworks, not prescriptions.

Intermittent Fasting (12–16 hours)

• Improves insulin sensitivity
• Encourages metabolic flexibility
• Often easiest to maintain consistently

Research Note
Human studies support metabolic benefits from intermittent fasting, particularly related to insulin regulation and inflammation markers.

24-Hour Fasts

• Deeper insulin suppression
• Greater reliance on fat metabolism
• Increased autophagy signaling

Many people report mental clarity and reduced inflammation during these fasts.

Research Note
Autophagy signaling likely increases during extended fasting windows, but exact thresholds differ between individuals.

3-Day Fast

• Significant metabolic and hormonal shifts
• Increased growth hormone
• Deeper cellular stress adaptation

This level is often explored in clinical or supervised settings.

Research Note
Multi-day fasts have shown measurable hormonal changes in humans, including increased growth hormone, but require caution and personalization.

5–10 Day Fasts

• Explored primarily for research, longevity, and therapeutic curiosity
• Profound metabolic changes occur

These fasts are not lifestyle tools, but areas of scientific interest.

Research Note
Evidence here is limited and mixed. Risks increase with duration, and outcomes vary widely based on individual health status.

Movement During Fasting: Why Some Keep Training

One of the most surprising reports from people who fast is this:

They don’t feel weaker — they often feel stronger.

Many individuals continue light to moderate exercise during fasting:

• Walking
• Mobility work
• Easy cycling
• Strength maintenance sessions

Some athletes report:

• Less joint pain
• Reduced inflammation
• Improved recovery
• Increased mental focus

Research Note
Reduced inflammation markers and increased fat oxidation may contribute to these effects, but responses are highly individual.

Electrolytes, Minerals & Supplements — What People Report

While not recommendations, many people choose to support their fasts with:

• Sodium or electrolytes
• Magnesium or potassium
• Non-caloric mineral support

These are often used to manage:

• Headaches
• Fatigue
• Dizziness

Research Note
Electrolyte balance is a known concern during fasting due to fluid and sodium shifts. Supplement use varies widely and lacks standardized human trials.

Black Coffee & Tea During Fasting

Black coffee and unsweetened tea are commonly used during fasting periods.

People report:

• Appetite suppression
• Increased focus
• Improved training energy

Coffee and tea contain polyphenols that may support metabolic processes.

Research Note
Black coffee and tea generally do not raise insulin significantly. Claims about coffee directly increasing autophagy are mechanistic and not conclusively proven in humans.

Why Many People Report Less Pain & Inflammation

A recurring theme among people who fast:

• Less stiffness
• Reduced soreness
• Improved joint comfort

This aligns with research showing fasting and intermittent fasting can reduce inflammatory markers associated with chronic pain and metabolic stress.

Research Note
Human studies show reductions in inflammatory markers such as CRP and TNF-α in some fasting protocols.

Myth Busting: Fasting Doesn’t Automatically Destroy Muscle

One of the biggest myths around fasting is muscle loss.

In reality:

• Growth hormone increases during fasting
• Fat becomes the primary fuel source
• Short-term fasting does not automatically cause muscle breakdown

Research Note
Muscle preservation depends on duration, activity, and individual physiology. Prolonged fasting without nutrition can increase protein breakdown over time.

The Takeaway: Fasting as a Reset Tool

Fasting isn’t about restriction — it’s about intentional recovery at the cellular level.

For many, it becomes a way to:

• Reduce inflammation
• Improve metabolic health
• Reset habits
• Start the year with clarity and discipline

Like all tools, fasting works best when approached with education, respect for the body, and an understanding that bioindividuality matters

At Asé Pure Naturals, we believe the start of the year is the perfect opportunity to reset — not with extremes, but with intentional, informed choices. Fasting, movement, and recovery are tools to support your body at a cellular level, reduce inflammation, and optimize overall wellness. Listen to your body, stay consistent, and embrace practices that make you feel stronger, clearer, and more energized.

Here’s to a year of health, resilience, and unstoppable energy.
— The Asé Pure Naturals Team