- Glucose is the last thing to change. Insulin rises for years to hold glucose normal, so a normal glucose is not reassurance — it is compensation.
- Fasting insulin under 6 µIU/mL is optimal. We routinely see 12, 15 and 18 in people whose glucose and HbA1c are flawless.
- This gives you ten to fifteen years of warning before a diabetes diagnosis — if anybody runs the test.
- Muscle is the largest glucose sink you have, and contracting muscle takes up glucose without needing insulin at all.
- Insulin resistance sits underneath a third of what we treat — PCOS, fatty liver, cardiovascular risk, low testosterone and weight loss resistance all trace back to it.
Why your glucose stays normal while the problem gets worse
This is the part of metabolic medicine that costs people the most years, and it is entirely avoidable with one inexpensive test.
Insulin's job is to move glucose out of the blood and into cells. When cells stop responding well, the pancreas does the obvious thing: it makes more insulin. More insulin still gets the job done, so glucose stays exactly where it should be.
That compensation can run for a decade or longer. During that time your fasting glucose is normal, your HbA1c is normal, and every annual physical tells you your blood sugar is fine. Meanwhile insulin is climbing, and elevated insulin is itself doing damage — driving fat storage, blocking fat release, raising blood pressure, promoting inflammation and suppressing SHBG.
Glucose only rises when the pancreas can no longer keep up. By the time a diagnosis of prediabetes arrives, the underlying problem has usually been present for ten to fifteen years.
Which is why we run fasting insulin on essentially everyone. It is inexpensive, it is widely available, and it is the difference between finding this early and finding it late.
The ten-year head start
The markers that actually find it
If you have had a lipid panel in the last year, you can calculate the triglyceride to HDL ratio yourself right now. Divide your triglycerides by your HDL. Above 3 suggests meaningful insulin resistance and is worth investigating properly.
The ten levers that reverse insulin resistance
Ranked by how much difference they make. The first three do most of the work.
Build and Use Muscle
The single most powerful lever. Skeletal muscle is your largest glucose disposal site, and contracting muscle takes up glucose through a pathway that does not require insulin at all. Two to three resistance sessions weekly does more for insulin sensitivity than hours of cardio.
What the evidence showsFasting insulin rises for years before fasting glucose or HbA1c move, because the pancreas compensates to maintain euglycaemia. HOMA-IR calculated from fasting insulin and glucose quantifies the compensation.Walk After Meals
Ten minutes. That is the whole intervention, and the effect on the post-meal glucose curve is substantial and immediate. It is free, it requires no equipment, and it is the change most patients actually sustain.
What the evidence showsSkeletal muscle accounts for the majority of insulin-mediated glucose disposal, and muscle contraction triggers GLUT4 translocation through an insulin-independent pathway — providing a route around the defect itself.Protein and Fibre First
Eating protein and vegetables before the starch measurably flattens the glucose response to the identical meal. Same food, different order, different insulin. This is one of the highest-return changes in nutrition.
What the evidence showsMeal sequencing studies show that consuming protein and vegetables before carbohydrate substantially reduces postprandial glucose and insulin excursions compared with the identical meal in reverse order.Fix Sleep
One week of restricted sleep measurably reduces insulin sensitivity in healthy people. You cannot out-eat or out-train a five-hour night, and sleep apnoea is dramatically under-diagnosed in exactly this population.
What the evidence showsPostprandial walking of ten to fifteen minutes measurably lowers glucose excursion, with effect sizes comparable to some pharmacological interventions in mild dysglycaemia.Correct Magnesium
Magnesium is a required cofactor for insulin signalling itself, and deficiency is common and largely invisible on a serum test because the body defends serum levels by drawing from bone. RBC magnesium is the measurement that matters.
What the evidence showsSleep restriction reduces insulin sensitivity substantially within a week in healthy adults, and the effect is reversible with recovery sleep. Obstructive sleep apnoea independently worsens insulin resistance.Remove Liquid Sugar and Refined Starch
Not all carbohydrate — liquid sugar specifically, and refined starch second. Fructose in liquid form goes straight to the liver, drives fatty liver and raises uric acid. This is the single dietary removal with the largest metabolic return.
What the evidence showsMagnesium is required for insulin receptor autophosphorylation and downstream signalling. Deficiency is common, associated with insulin resistance in prospective cohorts, and detected by RBC rather than serum measurement.Consider Berberine
A plant alkaloid that has matched metformin for glycaemic outcomes in several head-to-head trials, working through AMPK activation. For patients who want a botanical route or have not tolerated metformin, this is the most credible option available.
What the evidence showsBerberine has matched metformin for glycaemic outcomes in head-to-head randomised trials, acting largely through AMPK activation — the same pathway activated by exercise.Lower Inflammation
Inflammatory signalling interferes with the insulin receptor directly. Visceral fat is itself inflammatory, which creates a loop, and breaking into it from the inflammation side is often easier than from the weight side.
What the evidence showsInflammatory cytokines including TNF-alpha interfere with insulin receptor substrate phosphorylation directly. Visceral adipose tissue is metabolically active and a significant source of that signalling.Extend the Overnight Fast
Twelve to fourteen hours between dinner and breakfast gives insulin a genuine period at baseline. This is not extreme fasting, and for most people it means simply not eating after dinner — which is often the actual problem.
What the evidence showsThe triglyceride-to-HDL ratio is a validated and inexpensive proxy for insulin resistance that can be calculated from any standard lipid panel, with a ratio above 3.0 strongly suggestive.Correct Vitamin D and Omega-3
Both influence insulin sensitivity, and both are commonly deficient. Neither is a primary lever on its own, and together with the nine above they are frequently what moves a stubborn number the final distance.
What the evidence showsCortisol raises blood glucose through gluconeogenesis and promotes visceral fat deposition. Sustained elevation produces insulin resistance independent of dietary intake.What patients commonly experience under our care
When patients receive the proper guidance, here is what they commonly experience under our care.
- Week 1–2 — the afternoon crash goes. Flattening the glucose curve removes the three o'clock collapse and the evening carbohydrate pull almost immediately. This is the first thing patients notice and it arrives before any number moves.
- Weeks 3–6 — energy, sleep and waist. Steadier blood sugar improves sleep quality, and better sleep improves insulin sensitivity in return. The waistband typically changes before the scale does, because early loss is disproportionately visceral fat.
- Weeks 8–12 — the panel moves. Fasting insulin falling toward 6. HOMA-IR dropping under 1.5. Triglyceride to HDL ratio improving. ALT and GGT coming down as the liver clears. We retest here because this is the evidence that the mechanism has genuinely changed.
- Months 3–6 — the downstream conditions. This is where the value compounds. Blood pressure falls, lipids improve, testosterone rises in men, cycles regulate in women, and fatty liver reverses — because all of those were driven by the same thing.
If your glucose has always been normal but you feel like something is wrong, run the test that actually looks. Schedule a consultation and my team will measure what your annual physical does not, and build the plan around what we find. We will not stop until the root cause of every one of your health issues has been found and addressed.
Fasting insulin, HOMA-IR, triglyceride to HDL ratio, liver enzymes and uric acid — the panel that finds this ten years early.
Common questions
What is the best test for insulin resistance?
Fasting insulin, with HOMA-IR calculated from it alongside fasting glucose. Insulin rises for years while glucose stays normal, so a standard glucose or HbA1c will look fine for a decade while the problem develops. Optimal fasting insulin is under 6 µIU/mL; we regularly see 12 to 18 in people with flawless glucose.
Can insulin resistance be reversed?
In most cases we see, yes — and often substantially within twelve weeks. It responds to muscle, meal composition, sleep and a small number of targeted nutrients faster than almost anything else we treat. The earlier it is found, the more completely it reverses, which is the argument for testing before symptoms arrive.
What does prediabetes mean?
It means your glucose has risen above normal but not yet to diabetic levels. What it usually also means is that insulin resistance has been present for ten to fifteen years already, because glucose is the last thing to change. A prediabetes diagnosis is late notice rather than early warning.
Can I check for insulin resistance from my existing labs?
Partly, yes. If you have had a standard lipid panel, divide your triglycerides by your HDL. A ratio above 3 suggests meaningful insulin resistance and above 1.5 is worth looking at. It is a useful free surrogate, though fasting insulin is far more direct.
Is there an insulin resistance doctor near Nashville?
Yes. We are at 329 S. Royal Oaks Blvd in Franklin, Tennessee, about twenty minutes south of downtown Nashville. We run fasting insulin and HOMA-IR on essentially every patient, because this sits underneath a large share of what we treat.
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- Spiegel K, Leproult R, Van Cauter E. Impact of sleep debt on metabolic and endocrine function. The Lancet. 1999;354(9188):1435–1439.
- Yan J, et al. Berberine versus metformin in type 2 diabetes: a systematic review and meta-analysis. Journal of Ethnopharmacology. 2015.
- Shulman GI. Ectopic fat in insulin resistance, dyslipidemia, and cardiometabolic disease. New England Journal of Medicine. 2014;371(12):1131–1141.
- McLaughlin T, et al. Use of metabolic markers to identify overweight individuals who are insulin resistant. Annals of Internal Medicine. 2003;139(10):802–809.
This article is educational and reflects the published literature as of August 2026. It is not a diagnosis or a treatment recommendation for any individual, and any decision about your care belongs in a conversation with a licensed practitioner who has seen your history and your labs.