The value of R.Q. depends upon the nature of the respiratory substrates. The value of R.Q. is variable according to the substrate. The substrates having more oxygen in comparison to carbon, need less oxygen for oxidation and hence their R.Q. is more than 1, whereas those substrates where O2 is less than carbon, require more O2 for their oxidation and their R.Q. is less than one.
R.Q. of carbohydrates = 1.0
R.Q. of fats = 0.7 (1)
R.Q. of proteins = 0.8 (<1)
R.Q. organic acids = 1.33 (>1)
