I came across an interesting article just now. It's about how to choose which wine to drink if you're watching calories.
One fact in particular I found very interesting:
If you like red wine
Think geographically. As grapes ripen, sugar is created and either turns into alcohol or remains in the wine. So, choose cooler countries of origin, where the grapes contain less sugar and the wine less alcohol.
Avoid wine varieties grown in warmer climates as they have higher concentrations of natural sugars, so opt for colder climate reds like South Australian shiraz or Tasmanian pinot noir. As a general rule, a shiraz grown in South Australia will have a slightly lower sugar content than a shiraz grown in the Hunter Valley.
Don't you think that's interesting?