at some point, you have to get out of the laboratory and into the kitchen.

for example, most, if not all the macro charts I've seen, when you eat a banana, the unit of measure is one banana. but we all know bananas come in all different sizes. so what do you do? so you sit there and analyze the average size banana (how would you do that?) and then extrapolate that onto the size banana you are going to eat?

we live in a world of averages, so what I do is assume that 1/2 will be absorbed and 1/2 will stay in the pan. You have to admit, not all of it will be absorbed, and not all of it will stay in the pan. so what do you do? you make an assumption.