Glucose (fasting)

Routine annual

also fasting blood sugar, fbg, fpg, fasting plasma glucose

What it isGlucose is the sugar your body uses as primary fuel. Most of it comes from dietary carbohydrates, and the liver also synthesizes it on demand. After an overnight fast, the level reflects how well your liver, pancreas, and muscle tissue coordinate fuel handling without any incoming meal.

DoesGlucose powers nearly every cell and is the obligate fuel for the brain. Insulin and glucagon push it into and out of storage to keep blood levels in a tight band.

GoodStable fasting glucose signals intact insulin sensitivity and healthy metabolic flexibility — the foundation under longevity, body composition, and cognitive performance.

BadMildly elevated fasting glucose is the earliest commonly-tested fingerprint of insulin resistance and predicts type 2 diabetes, fatty liver, dementia, and cardiovascular events years out. Persistently high glucose glycates tissues, damages the endothelium, and accelerates every chronic disease of aging.

Standard

70–99 mg/dL normal; 100–125 prediabetes; ≥126 diabetes.

Optimal

75–85 mg/dL (lower is good)

Modifiers

Trends up slightly with age and after poor sleep; rises briefly with cortisol; fast for 10–12 hours before testing.

How to optimize

Lifestyle: Zone 2 cardio 3–4×/week and resistance training 3×/week drop fasting glucose 5–10 mg/dL over 8 weeks. Prioritize 7–9 hours of sleep — even one short night raises fasting glucose measurably. Walk 10 minutes after meals.
Diet: Cut refined carbs, sugar, and seed-oil-heavy processed foods. Build meals around protein, vegetables, and whole-food fats; eat carbs last in the meal. Time-restricted eating (10–12 hour window) helps.
Supplements: Berberine (500mg 2–3×/day pre-meal), magnesium glycinate (300–400mg/day), inositol (2g 2×/day), alpha-lipoic acid (600mg/day), chromium (200µg/day).
Peptides: Tirzepatide, semaglutide, retatrutide and MOTS-c all improve fasting glucose. GLP-1 agonists are the heaviest hitters.
Drugs: Metformin, GLP-1 agonists (semaglutide, tirzepatide, retatrutide), SGLT2 inhibitors, acarbose.

within Blood Sugar & Metabolic