Hi gavman, just saying hello one parent to another. Bev et al of course absolutely right. Wait a few minutes, then eat...We've had several instances of rushing a meal when my son is low (because he's also STARVING from being hypo!), and he's then had to stop eating and have some glucose to feel okay enough to eat...So it's worth doing in the first instance.
Another thing to try is juice and/or lucozade, as others say. My son can sometimes handle the idea of drinking something before eating more than he can crunching glucose...
Best of luck.