Fasting glucoseFasting blood glucose · FBG

Fasting glucose is the concentration of sugar in your blood measured after not eating for several hours, usually overnight. Taken away from the influence of a recent meal, it reflects how well your body holds blood sugar in a tight range at baseline.

It matters because a persistently raised fasting glucose is one of the earliest routine signs that the body is struggling to manage sugar — often appearing on the road toward prediabetes and type 2 diabetes, well before any symptoms. It sits near the centre of the wider metabolic-health picture.

In practice, fasting glucose is read alongside HbA1c and fasting insulin rather than in isolation, since a single reading can be nudged by stress, illness or a short fast. Regular exercise, muscle mass and avoiding a chronic energy surplus tend to keep it steady.