How can glycosuria be prevented?

Insulin if Diabetic. Glysosuria means glucose or sugar in the urine. Most common cause is diabetes. Primary diabetes can probably not be prevented and is due to insufficient or no Insulin production by the pancreas or production of Insulin antibodies. Secondary diabetes is most commonly caused by obesity, so avoid getting overweight. Glcosuria can occur normally in pregancy. Control hyerthyroidism and avoid xs alcohol.
Blood Glucose Low. The kidneys dump molecules smaller than albumen into the urine but in turn reabsorb 99% of water & small molecules so they do not end up exiting the kidneys; same for sugars. Sugar only spills into the urine if concentrations are so high, typically >300, as to overwhelm kidney's ability to reabsorb. Healthy blood glucose (one sugar) is ~70 to max <140 mg. Dl, average 100 or less, & never spills.