Those with diabetes struggle to balance adequate glucose levels in the blood and when they eat glucose in foods, they struggle to turn this into energy therefore the glucose stays within the blood creating high blood glucose levels. Blood glucose levels can be managed and monitored to maintain recommended levels. 

Certain foods such as white bread, white rice, sugar-sweetened beverages, potatoes have a high Glycaemic Index (GI) which mean they release glucose quickly which can spike blood sugar levels. Foods that are low GI such as whole grains, vegetables, legumes, nuts, meat, fish and so on – release glucose slower and more steady allowing diabetics to control blood sugar levels through dietary intakes. 

Like all health conditions, diabetes requires individual care and often has very individual requirements, before making any health or dietary changes ensure you consult with a trusted health care professional.