Fasting glucose above post-meal glucose is a common and mostly explainable pattern: overnight hepatic glucose output, dawn hormones, sensor and meter measurement error, and meal composition. Here is how to tell them apart with CGM data and lab numbers.
89 mg/dL is a normal glucose value, but a single number carries less information than most people assume. Here is how to read it given measurement error, and what to compute from a CGM trace instead.
What continuous glucose monitoring shows about post-meal glucose in people without diabetes: typical peak height, time to peak, return to baseline, and how to measure your own response properly rather than reacting to one alarming number.