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

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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⚠️ 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.