While there may be others, the lowest I have seen in the common food market (found at most grocery stores or easily bought online) is Peppridge Farm Light Breads. They range from 40 to 50 calories a slice, and have different kinds like High Fiber and Multi-Grain.
No Bread
Many coffees are 0 calorie.
The lowest is a regular hamburger with 250 calories.
Diet sodas.
granny smith
Banana bran
raimn noodles
Everclear is 150 calories per ounce which makes it lowest in calories compared to alcohol by volume.
Cod or tuna steak.
Most fruit is low calorie. Some of the lowest calorie fruits are strawberries, watermelon, and raspberries. Bananas tend to be higher in calories than other fruits.
Watermelon is the worst you can eat, Check that glycemic index.
I believe that the trumpet is the highest in te Brass famly, and the tuba is the lowest. In general, the bigger instrument is the lowest.
The kind of flax bread that I buy has 50 calories in it, I don't know if you buy the same kind