Raspberries have far and away the lowest amount of sugar. They have about the same amount as a turnip (4%), but with three times the fibre, and, of course, you eat them in far smaller quantities than turnips (by weight). They contain a source of prebiotics and they’re anti-inflammatory too. Seems like a good choice if you were craving some fruit. A serving is like an ounce or so, so you’re looking at 1g of sugar outweighed by 2g of fibre.