Nutrient Intake, Nutrient Storage and Nutrient Oxidation

This is going to be a bit of technical/unapplied article, I’m going to try to keep it short and to the point and mainly it serves as a background for some topics I want to talk about in the near future (especially alcohol) so just be forewarned as you start on this.  When people talk about diet, it’s common to divide the various nutrients that humans consume into two gross categories which are:

  1. Macronutrients: nutrients consumed in large amounts (‘macro’ = large)
  2. Micronutrients: nutrients consumed in small mounts (‘micro’ = small)

So macronutrient refers to protein, carbohydrates, fats and alcohol, those nutrients that, when they are consumed are generally consumed in gram or larger amounts.  The micronutrients refers to vitamins and minerals which are usually consumed in very small amounts (e.g. the DRI for Vitamin C is 60mg where 1mg is 1/1000th of a gram).  I’m not going to talk about micronutrients in this article and will only focus on the macronutrients, specifically protein, carbohydrate, fat and alcohol.

I’m also going to assume that you’re getting your nutrients through food and it’s going in through your mouth. Certainly nutrients can be given via infusion but this is usually done in a hospital setting (sometimes athletes will rehydrate and carb-load with IV fluids and glucose, mind you) and I’ll assume you’re not doing that.


Digestive Efficiency and Your Poop

Clearly anything you eat has to go through the process of chewing, swallowing and into the stomach for digestion.  There a bunch of stuff happens where the nutrients are broken down to one degree or another.  And either they get absorbed (moving into special cells to be released into the bloodstream, or lymphatic system in the case of dietary fats) or not.  If you’re particularly interested in the digestion processes of the different macronutrients, I’d refer you to the specific articles: