Nutrition Science and Everyday Application - beta v 0.1

CLASSIFICATION OF NUTRIENTS 33
A YouTube element has been excluded from this version of the text. You can view it online here: https://openoregon.pressbooks.pub/
nutritionscience/?p=748
VIDEO: “Pellagra video” by Teresa Johnson, YouTube (June 20, 2012), 5:49 minutes.
ENERGY-YIELDING NUTRIENTS
The macronutrients—carbohydrate, protein, and fat—are the only nutrients that
provide energy to the body. The energy from macronutrients comes from their chemical
bonds. This chemical energy is converted into cellular energy that can be utilized to perform
work, allowing cells to conduct their basic functions. Although vitamins also have energy
in their chemical bonds, our bodies do not make the enzymes to break these bonds
and release this energy. (This is fortunate, as we need vitamins for their specific functions,
and breaking them down to use for energy would be a waste.)
Food energy is measured in kilocalories (kcals). A kilocalorie is the amount of energy