We cannot control our genes, but we can control the size of our jeans! Exercise prevents sugar from accumulating in the blood, helps the body ability to use insulin and helps control weight.  Losing just 5% of our current weight can lower your risk for complications from diabetes. Thats a start. 
Your ultimate goal is to incorporate aerobic exercise, strength training and flexibilty exercises into your overall fitness enhancement programme. 
Here is a list of exercises you can incorporate during your week that will greatly influence your "fitness level". 
walking up and down hills 
jogging 
bike riding 
stationary bike in the home 
tennis 
swimming 
yoga 
bowling 
dancing 
low impact areobics or water areobics 
ice skating 
stength training with elastic bands, tubes or weights 
daily flexibility exercises or stretching exercises before activities