I hope this is going to be more like The Empire Strikes Back rather than Back to the Future II.
There are more differences between foods with the same number of calories listed than just how much your body absorbs and how much passes through.
The ileal break. When sugars enter the end portion of your small intestine, the ileum, it sends a signal to your brain to shut down your hunger. Foods with a lot of fiber take a long time to break down and there are sugars left when they get to your ileum to trigger the feeling-full signal. If you eat or drink foods without fiber, such as Coke, which has zero fiber, all the sugars get absorbed in the beginning parts of your intestines before they get to your ileum (end part) and no trigger is set. Without the lack of hunger signal, (ileal break), a tendency to overeat may happen.
Volume. Our stomachs will feel more full after consuming 5 cups of snow peas compared to one can of Coke.
Chewing. One of the ways your brain senses you have eaten is from the act of chewing. No chewing required from Coke.
Timing. The amount of time it takes to consume 5 cups of snap peas compared to a can of Coke is huge.
Blood sugar. Rapid absorption of sugars in your system causes an increase of sugar in your blood and results in an insulin spike.
Who would want us to think a calorie is a calorie? For most of us, it is what we believe because it is what we have been told for decades and it is difficult to let go of long held beliefs. More towards the dark side, the people at Coke want you to believe that a calorie is a calorie—even if they know better (and they do). If they can keep you believing this myth, then their product is just another 140-calorie choice rather than the high fructose corn syrup junk it is.