Why is fasting sugar normal but post-meal readings high?

This is a common and clinically meaningful pattern, especially in South Asians, and it often appears years before fasting glucose rises. It happens because the first-phase insulin response — the rapid burst after eating — declines early, while the body can still hold fasting levels steady. The practical implication is that a normal fasting sugar does not exclude a problem, and testing only fasting glucose misses a lot of early dysglycaemia. Ask for an HbA1c or a post-meal reading if you have risk factors. High post-meal spikes are also the ones most responsive to walking after eating.