Heart, metabolismmg/dl
Fasting glucose
Optimal
72–90 mg/dl (4.0–5.0 mmol/l); above 100 prediabetes
Why
The cheapest metabolic marker, but a late one: the pancreas compensates for years before fasting glucose rises. So measure insulin and HbA1c alongside. A “normal” value above 90 already tracks with higher dementia risk (Crane 2013).
How often
Yearly; every six months with prediabetes, or a 2-week CGM once a year.
What moves it
Weight loss (most effective), strength training (muscle = glucose store), a 10-minute walk after meals, fibre, 7+ hours of sleep, metformin/berberine.
Last reviewed: 6 September 2026
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