It's simpler to get in bars (though they tend to run out of diet coke fast), and... well, I never bothered to check the carbohydrate contents of rum; just decided to go with the simplest option ;).
ethanol has a high caloric content but almost none of those calories can be absorbed by the body. It is a fundamental flaw in the way food calories are measured. To measure the calories of food you put the food in a sealed container under a vial of water and burn it, the food has 1 calorie for ever degree centigrade it made a liter of water rise. ethanol obviously burns extremely well so by this test it has high caloric content but that does not mean your body can convert ethanol to fat, sugar, ATP or anything else useful to the body. The vast majority of it is processed by the liver and expelled by the kidneys
Calories is not the metric important for me here (every alcoholic beverage has plenty of it, so standard caution applies), it's carbohydrate count - too much and you're out of ketosis for good.
I need to get back on... I'm a big boy (6'2 300lbs) and I was doing great on it but eventually stopped because of an impromptu "Want to be in my wedding in a month?" invitation that required me to stop losing the weight because otherwise I'd be swimming in my tuxedo at the wedding.. Never got back on. I miss it.