What Happens in Your Body During a Fast (First 48 Hours Explained)

What Happens in Your Body During a Fast (First 48 Hours Explained)

Author: The Fasting Method May 19, 2026 Duration: 24:17

Fasting is not a switch — it's a sequence.

Episode #258
🎙️ In this episode, Coach Lisa breaks down what's really happening in your body during the first 24–48 hours of fasting.

From glycogen depletion to fat burning and gluconeogenesis, Lisa explains why fasting can feel slow or frustrating at first — especially for newer fasters — and why consistency is what helps the body become more metabolically flexible over time.

This episode walks through the physiology of fasting in a practical, easy-to-understand way so you can better understand what your body is doing and trust the process.

👉 What you'll learn:
• What the body uses for fuel first during a fast
• Why fat burning doesn't happen immediately
• How glycogen depletion works
• What gluconeogenesis actually is
• Why low carb eating supports fasting
• How movement helps accelerate the switch to fat burning
• Why consistency matters more than dramatic fasts

⏱️ Timestamps
00:00 — Why fasting is a sequence, not a switch
00:26 — Why the first 48 hours can feel frustrating
01:58 — Why consistency matters for metabolic flexibility
02:39 — What is the body actually using for fuel first?
04:26 — Why doesn't fat burning happen straight away when we begin a fast?
06:11 — How long does it take to switch from glycogen to fat burning?
07:23 — Does the body get better at making the switch over time?
09:18 — Why consistency trains the body
09:56 — What is gluconeogenesis and when does it happen during fasting?
12:56 — Why how you break your fast matters
14:12 — If we eat low carb, does the body still refill glycogen stores?
16:35 — Does movement or exercise help use up glycogen faster?
19:34 — Why fasting may not "feel" effective yet
19:42 — Could the early glycogen phase explain slow results at first?
21:26 — Why the first few weeks are foundational
22:08 — Key fasting takeaways and recap
23:22 — Listener question: when did fasting start to feel easier for you?

📝 Transcript
The transcript for this episode is available on our website:
https://www.thefastingmethod.com/podcasts/

💛 Community Support
Join The Fasting Method Community for guidance, accountability, and coaching support:
https://www.thefastingmethod.com/community/

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📣 Connect With Us
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⚠️ Disclaimer
This podcast is for educational purposes only and is not a substitute for professional care by a doctor or other qualified medical professional. You should always speak with your physician or other healthcare professional before doing any fasting, changing your diet, taking or adjusting any medication or supplements, or adopting any treatment for a health problem.

The use of any products or services purchased does not create a healthcare provider–patient relationship.

Information and statements regarding dietary supplements have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease.


For anyone navigating the world of intermittent fasting, sorting through the noise can be the hardest part. The Fasting Method Podcast cuts through that confusion with clarity and authority. Co-hosted by recognized experts Megan Ramos and Terri Lance, Ph.D., this podcast is built on a foundation of real science and practical application. The conversations here move beyond simplistic tips to explore the nuanced physiology of fasting, the psychological hurdles, and the sustainable strategies that lead to lasting health changes. You’ll hear detailed explorations of metabolic adaptation, hormone regulation, and the social complexities of changing one's eating patterns, all grounded in the hosts' extensive clinical and research experience. This is a space where listener questions drive the dialogue, making each episode a direct address to the real-world challenges people face. Tune in for a candid, evidence-based resource that treats fasting not as a trend, but as a deeply personal tool for wellness. The discussions on this podcast are designed to empower you with knowledge, demystify the process, and provide a supportive audio companion for your journey.
Author: Language: English Episodes: 50

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