This question was prompted by me making myself a cup of tea and noticing that my box says each tea bag is zero calories which made me wonder if it were truly zero or some small fraction that and would add up to a few calories if I I could somehow brew and drink the entire box of one hundred bags. Would the FDA allow this?
Absolutely. Rounding is used in calorie counts. Check out these diet flavor sprays.. They are listed as zero calories because there are hundreds of fairly intense sprays in a bottle but I read an analysis that if you drank the bottle, it would be a few hundred calories. Of course, this isn’t much worry as a practical matter.
Thanks. That’s what I assumed.
Do you happen to know what percentage it has to be before something can be rounded down to zero? I am assuming that with something like tea, where a dozen bags can be used at once, it would be something in the very low hundredths or maybe as much as a tenth but could it actually be as much as 0.499%?
Yup, values are rounded, per this page from the FDA website; check out numbers 34 and 36 on that list, for instance. Calories are rounded to the nearest 5 calories (nearest 10 if over 50 calories total), fat grams to the nearest full gram - so a half gram of fat would be rounded down to 0 g, and a 2 calorie item would be listed as zero.
Sorry, I missed the caveat on the page. An item below 5 g of fat is rounded to the nearest half-gram, so a food with 0.2 g of fat would be rounded down to 0.
Thanks for the link, Ferret Herder. That is exactly what I was wanting.
So, given there’s some rounding, do you think that the stuff that flavors tea has any caloric value at all?
calories under 5 can be listed as 0.
you have to check the serving sizes too. For example, “no-calorie” spray butter has such miniscule serving sizes that one normal-sized spray is several servings.
Diet soda tends to have about 3-5 calories per serving. tea has fewer calories than diet soda, I believe, but you can still squeeze about 10 calories out of most bags.
Nothing that you will ever consume other than water and air truly has zero calories. I’m not even sure about water. I suppose unless it’s ultra-purified, there are impurities that contain calories.
I don’t think that’s quite correct.
The FDA says “rounded to the nearers 5 calorie increment.” So calories up to 2.5 could be rounded down to zero, 2.51 or more would be rounded up and listed as 5 calories.
But you are quite right about watching the serving size. Many foods are listed with misleadingly low calories, because the serving size is much smaller than people commonly eat. 12-ounce cans of pop, with a serving size of 8 ounces. Candy bars with a serving size of half the bar. A 16 ounce package of 8 doughnuts, with a serving size of 1 ounce (half a doughnut). All attempts to trick customers, by giving a ‘serving size’ that is smaller than the amount people normally eat.
The net caloric intake of a food item that has 2 calories is probably near 0 anyway.
Walk over to cupboard, open door, reach up, grab a can of cooking spray, glance at label, move to pan, pry off cap, squirt pan, replace cap, put can back in cupboard, shut cupboard, return to stove, etc, etc.
Okay, maybe you just blasted 2 - 3 calories onto your food, but it probably took 2 calories of effert to accomplish the task (plus some digestion). 
Also, don’t forget that cooking food takes away some of the calories that are listed on the box. At least that’s what I assume. Calories are measured in a process of bomb calorimetry where the food is burned as fuel in a known quantity of oxygen. the total system temperature is measured and the amount that the oxygen produced is subtracted. What’s left is the caloric output of the food fuel. So, if the food can give up its heat energy in a bomb calorimeter, can’t it be given up in cooking too?
Before the most recent labeling systems, Olives could label themselves as ;ow fat" food, as each olive contained less than a gram of fat. Of course, olives get over 90% of their calories from fat (and who eats just one, anyway?) so this was seriously misleading.
But as for tea, it’s pretty damn close to 0, even if you drank 100 bags. Oddly, those little bags of artificial sweeteners often contain a tad of real sugar so as to flow better.
Olives are indeed an “ow fat” food.
Wasn’t he a villain on Hawaii Five-0?