Straight rum, yeah, but most common brands available do have some added sugar unless otherwise specified e.g. Captain Morgan, Malibu Rum, Bacardi Rum (except for Light and Gold which have 0g). My diabetic father-in-law just tends to avoid rum in general because it's too much hassle making sure it's one without any added sugars.
And the sugar is consumed in the fermentation process.
Straight rum, yeah, but most common brands available do have some added sugar unless otherwise specified e.g. Captain Morgan, Malibu Rum, Bacardi Rum (except for Light and Gold which have 0g). My diabetic father-in-law just tends to avoid rum in general because it's too much hassle making sure it's one without any added sugars.