The Benefits of Fasting: What Happens in Your Body and How It Heals You

What Is Fasting and Why It Works

Fasting has been practiced for centuries for spiritual, cultural, and health reasons. Today, modern science confirms what ancient traditions always knew — that giving your body a break from constant eating can have profound effects on cellular health, metabolism, inflammation, and longevity.

When you fast, your body shifts from focusing on digestion to repair and rejuvenation. Below, we’ll explore what happens in the body during a fast, what the research says about its benefits, and how to fast safely and effectively.

0–12 Hours of Fasting: Using Stored Energy

When you stop eating, your body begins using stored glucose (glycogen) from the liver for energy.

• Insulin levels drop, allowing your body to start burning fat more efficiently.

• Blood sugar stabilizes, helping regulate energy and mood.

• Digestive rest: Your gut takes a break, allowing for repair and reduced inflammation.

🧠 Research:
A study published in Cell Metabolism (Longo & Panda, 2016) found that fasting periods of 12–14 hours help regulate circadian rhythms and improve key metabolic markers such as insulin sensitivity and blood sugar control.

12–24 Hours of Fasting: Fat Burning Begins

Once glycogen stores are depleted, your body begins burning fat for energy through a process called ketosis.

• Fatty acids are converted into ketones, a clean energy source for the brain and muscles.

• Inflammation and oxidative stress begin to decrease.

• Growth hormone (GH) levels can increase up to 2–5× baseline, aiding in tissue repair and muscle preservation.

🔬 Research:
Hartman et al. (Journal of Clinical Endocrinology & Metabolism, 1992) showed that fasting significantly increases GH secretion, improving fat metabolism and muscle maintenance.

24–48 Hours: Cellular Cleanup and Repair (Autophagy)

After about a day of fasting, your body activates autophagy — a natural cellular “cleanup” process.

• Damaged or dysfunctional cells are broken down and recycled.

• This process helps reduce inflammation, slow aging, and support cellular regeneration.

• The immune system becomes more efficient at removing old or damaged immune cells.

🔬 Research:
Yoshinori Ohsumi won the 2016 Nobel Prize in Physiology or Medicine for his discovery of autophagy, confirming its vital role in anti-aging and disease prevention.

48–72 Hours: Deep Repair and Immune Reset

After two to three days of fasting, profound physiological changes take place:

• Insulin levels remain low, promoting continued fat burning.

• Ketones reach higher levels, fueling the brain and reducing cravings.

• Stem cell regeneration begins — especially in the gut and immune system.

• Inflammatory markers continue to decline.

🔬 Research:
A 2014 Cell Stem Cell study from the University of Southern California (Longo et al.) found that prolonged fasting (48–72 hours) triggers stem cell production and regenerates parts of the immune system.

How to Fast Safely: Tips for Beginners

Fasting can be highly beneficial, but it should always be done with awareness and respect for your body.

✅ 1. Stay Hydrated
Drink plenty of clean, filtered water. Aim for half your body weight (in ounces) per day. Herbal teas and black coffee are typically fine during fasting windows.

✅ 2. Support Electrolytes
Add a pinch of high-quality sea salt or Himalayan salt to your water to maintain electrolyte balance — especially sodium, magnesium, and potassium.

✅ 3. Ease In
If you’re new to fasting, start with a 12-hour overnight fast (for example, 7 PM to 7 AM) and gradually increase the fasting window to 14–16 hours as your body adapts.

✅ 4. Break the Fast Gently
When it’s time to eat, choose nutrient-dense, whole foods — clean proteins, healthy fats, and colorful vegetables. Avoid breaking your fast with sugary or processed foods, which can spike insulin and undo many benefits.

✅ 5. Special Considerations
If you’re pregnant, breastfeeding, diabetic, or managing other chronic health issues, consult your healthcare provider before fasting.

Final Thoughts: Give Your Body Time to Heal

Fasting isn’t just about eating less — it’s about allowing your body time to rest, repair, and rebalance. From improved energy and focus to cellular renewal and immune support, fasting can be a natural way to enhance your overall wellness.

When combined with consistent chiropractic care, proper nutrition, and movement, fasting supports your body’s innate ability to heal and function at its best.

Small, consistent changes — like mindful fasting and regular chiropractic adjustments — often lead to the biggest long-term results.

Want to Learn More About Functional Health?

At Valley Family Wellness, we help patients create personalized health plans that include chiropractic care, nutritional guidance, and functional lab testing to help your body thrive naturally.

📍 Serving families in Staunton, Virginia — schedule your visit to learn more about fasting and holistic wellness.