A hemoglobin A1c of 5.2% is below the 5.7% that the American Diabetes Association (ADA) uses as the lower bound for prediabetes.[1] Your doctor tells you everything looks great and to come back in a year. The catch is that A1c and fasting glucose can stay in the normal range while the body compensates for reduced insulin sensitivity, so they don’t show the compensation itself.
To understand why, look at what the insulin-producing cells in your pancreas do when sensitivity to insulin declines. When muscle and fat cells stop responding to insulin as well as they should, glucose is cleared less efficiently. The normal response of the pancreatic beta cells is to increase insulin secretion, and this compensatory hyperinsulinemia can hold fasting glucose in the normal range for a time, until the compensation is no longer sufficient.[2] When insulin resistance is accompanied by beta-cell dysfunction, control of blood glucose fails.[3] This is the compensation phase: blood sugar looks normal because insulin output is higher. That is not a state anyone can see on a standard report.
Under the ADA criteria, prediabetes is an A1C of 5.7-6.4% or a fasting plasma glucose of 100-125 mg/dL. The ADA also notes that risk for all of these tests is continuous, extending below the lower limit of the range and growing disproportionately at the higher end.[1] So a number inside the normal range is not a guarantee of low risk, and it is not a diagnosis of a problem either.
Fasting insulin shows how much insulin the body is making to hold glucose steady. It is not part of the ADA criteria for prediabetes, and the sources cited here do not give a diagnostic cutoff for it, so interpreting a result belongs with your clinician. HOMA-IR is a calculation from fasting glucose and fasting insulin that was developed in 1985 to estimate insulin resistance. In its original validation it correlated with the euglycemic clamp (Rs = 0.88), though the authors noted that its low precision limits its use (coefficient of variation 31% for insulin resistance).[4] That is a reason to treat a single HOMA-IR value as a prompt for a conversation, not a verdict.
The fix at this stage isn’t a pill from a blog post. These are three habits with research behind them, each studied in specific groups. Talk with your clinician before changing your routine, especially if you take glucose-lowering medication.
Carbohydrate sequencing – eating starches and sugars at the end of the meal, after protein and vegetables. In 16 people with type 2 diabetes who ate the same meal on three days, eating carbohydrate last produced a 53% lower glucose area under the curve and a 54% lower glucose peak than eating carbohydrate first, along with lower insulin excursions.[5] It’s a different order for the same food. The participants had type 2 diabetes, so the result may not apply to people with normal glucose.
Muscle glucose uptake matters because skeletal muscle is where about 80% of glucose uptake occurs under euglycemic hyperinsulinemic clamp conditions.[2] In a study of 10 people with type 2 diabetes and 7 healthy men, training one leg with strength exercises for 30 minutes three times per week for 6 weeks increased insulin-stimulated glucose clearance and GLUT4 protein content in the trained leg.[6] Breaking up sitting also appears to help: a meta-analysis of seven one-day crossover trials found light-intensity walking to be a better way to interrupt sitting than standing.[7]
The overnight fasting window has early evidence. In a 5-week crossover trial in men with prediabetes, early time-restricted feeding (a 6-hour eating period, with dinner before 3 p.m.) improved insulin sensitivity compared with a 12-hour eating period, even though participants ate enough to maintain their weight.[8] That is a stricter schedule than a 12-hour overnight gap, the study was a proof-of-concept trial in men with prediabetes, and it did not test a 12-hour overnight fast on its own.
Counterpoint: what if fasting insulin is normal but blood sugar still spikes after meals? Fasting measures don’t capture what happens after you eat. The ADA criteria also include a 2-hour glucose of 140-199 mg/dL during a 75-g oral glucose tolerance test as a prediabetes range.[1] If you are concerned about after-meal spikes, ask your clinician whether that test makes sense for you.
The real signal isn’t the number itself. It is the compensating effort behind the number. Bettering Me suggests talking with your clinician about whether fasting insulin or an oral glucose tolerance test fits your situation, and about meal order, resistance training, and your overnight eating window as habits to try. A few small, manageable changes are easier to start before a number crosses a cutoff than after.
References
↑︎ American Diabetes Association Professional Practice Committee. 2. Diagnosis and classification of diabetes: Standards of Care in Diabetes-2025. Diabetes Care. 2025;48(Suppl 1):S27-S49. DOI: https://doi.org/10.2337/dc25-S002
↑︎ DeFronzo RA, Tripathy D. Skeletal muscle insulin resistance is the primary defect in type 2 diabetes. Diabetes Care. 2009;32(Suppl 2):S157-S163. DOI: https://doi.org/10.2337/dc09-S302
↑︎ Kahn SE, Hull RL, Utzschneider KM. Mechanisms linking obesity to insulin resistance and type 2 diabetes. Nature. 2006;444(7121):840-846. DOI: https://doi.org/10.1038/nature05482
↑︎ Matthews DR, Hosker JP, Rudenski AS, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28(7):412-419. DOI: https://doi.org/10.1007/BF00280883
↑︎ Shukla AP, Andono J, Touhamy SH, et al. Carbohydrate-last meal pattern lowers postprandial glucose and insulin excursions in type 2 diabetes. BMJ Open Diabetes Res Care. 2017;5(1):e000440. DOI: https://doi.org/10.1136/bmjdrc-2017-000440
↑︎ Holten MK, Zacho M, Gaster M, et al. Strength training increases insulin-mediated glucose uptake, GLUT4 content, and insulin signaling in skeletal muscle in patients with type 2 diabetes. Diabetes. 2004;53(2):294-305. DOI: https://doi.org/10.2337/diabetes.53.2.294
↑︎ Buffey AJ, Herring MP, Langley CK, et al. The acute effects of interrupting prolonged sitting time in adults with standing and light-intensity walking on biomarkers of cardiometabolic health in adults: a systematic review and meta-analysis. Sports Med. 2022;52(8):1765-1787. DOI: https://doi.org/10.1007/s40279-022-01649-4
↑︎ Sutton EF, Beyl R, Early KS, et al. Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metab. 2018;27(6):1212-1221.e3. DOI: https://doi.org/10.1016/j.cmet.2018.04.010
Kurt Greiner
Kurt is a digital strategist and IT professional blending emerging technology with practical application to help businesses and individuals streamline their digital presence. His current work focuses on the intersection of intentional living and technological resilience, exploring how individuals can leverage modern tools to navigate the second half of life with purpose.
Leave a Reply