This class of drug basically allows the kidneys to "spill more glucose" into the urine. The simple version is the "beans" have a threshold of mg 180mg/dL of blood glucose before intrinsically spilling glucose in the urine in an attempt to maintain euglycemia. So the Jardiance class drugs "amplify this effect" and helps the kidneys along a little further reducing blood sugar levels. This increses the risk GU tract  infections...why, more food source for any opportunistic bacteria hanging arond. 

Now logical thinking would suggest decreasing the glycemic index in the diet should have a similar effect. We have all heard of the " diet controlled diabetic". Eating high glycemic index foods is likely the root cause of the type 2 diabetic (metabolic syndrome) crisis, which leads to the inherent complications when the excess "sugar moiety" attaches itself to the insides of the "arteries and nerves"  and turned into visceral and subcutaneous fat. Very simpistic in explanation but drives the point home.