... You're eating something with an ingredient that is "sugar free."

This rule can be explained using very simple mathematics. Anything that is listed as "sugar free" generally contains zero calories. My very basic math skills remind me that zero multiplied by anything (read: when mixed together with other ingredients, in our case) equals zero.

So essentially, any food item x a sugar free ingredient containing zero calories = zero calories for the food as a whole.

This means that a cookie containing a sugar free sweetener such as Splenda or Equal has no calories in it. Same story for cookie dough ice cream, hot chocolate, or other tasty treats, so as long a sugar free substance is thrown in the mix. Happy calorie-free eating!