 Get a continuous glucose monitor. And there are ways of doing this without even a doctor's prescription. And you can find out a lot about how you react to different foods. And it may differ from day to day. It may be that after exercise, you react less. Or that if you have a bad night's sleep, or if you're jet lagged, you may have a different reaction to an identical meal. So there's a lot of factors in play. Or certainly if you're ill, that'll...