Oh this always comes up -

those wine counts of 3 or 4g per glass of wine are WRONG. WRONG WRONG WRONG! The reason they put that is it is what is left over after protein, ash, alcohol etc have been accounted for.

what you need to find out is how much RESIDUAL SUGAR per litre is in that particular wine. For a dry red wine it is usually about 3-4g per LITRE, not glass.

The rest could be glycerol, which forms a part of fat - whether or not that will effect weight loss is debatable, seeing as it's ok to eat lots of fat on low carb.