Expert Q&A

Does anyone have a normal A1C, but high insulin while doing intermittent fasting during the weight loss plateau phase?

Understanding the Disconnect Between Normal A1C and High Insulin

In my 35 years of clinical practice, I frequently see patients stuck in a weight loss plateau while practicing intermittent fasting (IF). They proudly report a normal A1C of 5.4 or below, yet their fasting insulin remains elevated at 12–18 uIU/mL. This mismatch signals underlying insulin resistance that standard A1C testing misses. A1C reflects average blood glucose over 90 days, but it doesn’t reveal how hard your pancreas works to keep glucose in range. High insulin means your body is compensating for resistance caused by lingering inflammation, toxins, or hormonal shifts common in the 45–54 age group.

During the plateau phase of my The 30-Week Tirzepatide Reset protocol, this pattern appears in about 40% of patients. Hormonal changes in perimenopause or andropause exacerbate it, making fat loss feel impossible despite disciplined IF windows of 16:8 or 18:6. The good news? This is fixable without escalating medication doses or adding complex meal plans that insurance won’t cover.

Why Intermittent Fasting Can Mask the Problem

IF is powerful for improving insulin sensitivity, but on a plateau it can backfire if foundational issues remain unaddressed. When you compress eating into a short window without removing dietary lectins and ultra-processed carbs, the body stays in a defensive state. Joint pain often prevents movement, further slowing metabolism. In our Nashville clinic and CFP Fit Now telehealth, we measure fasting insulin alongside C-peptide and HOMA-IR to get the full picture—far more revealing than A1C alone.

The two biggest mistakes I see are relying solely on IF or tirzepatide without rebuilding metabolic freedom. Patients regain weight because they never corrected the root causes: lectin-driven gut inflammation, toxin burden, or broken hunger signals. My book details exactly how to avoid this through three 70-day cycles that integrate low-dose tirzepatide cycling, real foods, and targeted support.

The 30-Week Tirzepatide Reset Approach to Break the Plateau

Follow the 69 Transformation Steps outlined in The 30-Week Tirzepatide Reset. Switch to our lectin-free, low-carb plan with 221 simple recipes—no complicated schedules required. Cycle one box of tirzepatide at micro-doses (starting 0.5–1 mg) while using our Brown Detox Drops daily to clear liver burden that elevates insulin. Add 20-minute Japanese-style walking intervals most days; these gentle movements are joint-friendly and boost mitochondrial function without gym time.

Incorporate red light therapy three times weekly via our Unlimited Red Bed Club to reduce inflammation and support hormonal balance. Track body composition weekly instead of daily scale obsession. For diabetes and blood pressure management, we’ve seen average drops of 1.6 points in A1C and 15–20 mmHg in systolic pressure by week 10 when insulin normalizes below 8 uIU/mL. Chaotic IF in maintenance—varying windows day to day—prevents adaptation and sustains results long-term.

Real Patient Outcomes and Lasting Metabolic Freedom

Consider John, a 52-year-old with normal A1C but fasting insulin of 16 during his plateau. After 12 weeks on the protocol—lectin-free meals, Detox Drops, low-dose cycling, and red light—his insulin fell to 6.2. He lost 28 pounds, eliminated joint pain, and maintained off medication. Stories like his prove you don’t need lifelong injections or willpower battles. The protocol restores hypothalamic signaling so your body naturally defends a lower weight. Start with one cycle, measure insulin at weeks 0, 10, and 20, and watch non-scale victories compound. This is true metabolic reset, not another failed diet.

💬 What the Community Says

Forum threads on this topic show a split among 45-54 year olds in mid-income brackets. Many report frustration after months of 16:8 or 18:6 intermittent fasting with stable A1C readings around 5.3-5.6 yet fasting insulin stubbornly above 10. A vocal group shares success stories after adding detox supplements, walking routines, or switching to lectin-free eating, often citing 15-25 lb breakthroughs. Others debate whether insurance-covered labs miss the issue entirely and complain about conflicting online advice. Joint pain and hormonal shifts frequently surface as barriers, with users embarrassed to push doctors for advanced testing. Most agree the plateau phase feels uniquely defeating after previous diet failures, though a subset praises low-dose GLP-1 cycling paired with real-food changes for finally lowering insulin without regain. Overall sentiment leans toward cautious optimism once root causes beyond A1C are addressed.
Clark, R. (2026). Does anyone have a normal A1C, but high insulin while doing intermittent fasting. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/does-anyone-have-a-normal-a1c-but-high-insulin-while-doing-intermittent-fasting-during-the-weight-loss-plateau-phase
Russell Clark, FNP-C, APRN, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

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