So, I ate the Macro Nutrients my Body Needs, now what happens Next?

All this talk about healthy eating has paid off! You went to lunch with a coworker and instead of your usual half-pound burger and french fry, you opted for a nice lunch sized salad topped with grilled salmon. It was served with a whole grain roll and you had water with lemon to drink. So, now that your body has been provided with the essential macro nutrients in optimal form, what comes next? How will they be used?

Digestion is both mechanical and chemical in nature. 

Mechanical Digestion

Digestion begins in the mouth as food is chewed and broken down for passage through the esophagus into the stomach. An enzyme present in the saliva (salivary amylase) works to break down carbohydrates immediately. 

Babies have a salivary enzyme called lactase which assists with the breakdown of protein. This is unique to babies because most often, protein is digested in the stomach.

Food is churned by the stomach and mixed with bile until it is released as chyme into the small intestine.By the time, the food becomes chyme, it has been broken down and is made ready for absorption. Most of the digestion and absorption takes place in the small intestine and the remains are released into the large intestine where preparation for elimination is made.

Chemical Digestion

There are many chemical processes involved with the process of digestion. First, enzymes within the mouth begin to breakdown starch. Once the food, is transported to the stomach, it is mixed with gastric juices. In the small intestine, bile is added. Pancreatic juices containing bicarbonate help to neutralize stomach acid (Sizer & Whitney, 2013).

All of these processes are pretty complex and I always find for myself, it helps to get a visual representation of the process to aid in understanding. Here is a brief video to demonstrate both processes. I hope this helps you see how those healthy foods you ate will be processed and used by your cells to maintain optimal body functioning. Bon Appetite!

References

Mechanical v Chemical Digestion. (n.d.). Retrieved August 25, 2014, from https://www.youtube.com/watch?v=xTKjZOhq-_Q

Sizer, F. & Whitney, E. (2013).  Nutrition: Concepts and Controversies
(13th ed.).  Mason, OH: Cengage Learning.