If natural flavors are extracts (like vanilla extract which has 40 cal per tbsp) shouldn’t they have calories?
Is this why diet drinks can stall weight loss?
Diet drinks can stall weight loss because they have other impacts on physiology than pure CICO. There are hormonal responses to many diet drinks that can impact fat, muscle, and water weight.
The reason that natural flavors are “zero” calorie is because there is so little of them in each serving. It’s well within the margin of error allowed by the USDA. If you round it up to 1 instead of 0, you wouldn’t be wrong to do that. It’s still marginal and barely worth accounting for from a caloric intake standpoint.