Digestion Case Study

The Digestion Case Study was about three girls who wanted to learn about what are carbohydrates exactly and which are undigested. They read an article about how there is a vaccine being given in Australia to sheep and cattle in order to reduce harmful methane gas emissions from the animals and help take the heat off global warming.

The girls became curious about carbohydrates and listed what they had eaten so far:

For breakfast – Cheerios with oat bran, a tall Latte with skim milk, and a PowerBar


For Lunch – Coke and a salad with lettuce, cabbage, tomato, shredded carrot, green peas, kidney beans, and tuna fish


Every single item listed contains carbohydrates except for tuna fish. In order to help identify foods containing carbohydrates, here are some rules:

  1. Anything that contains sugar, starch, or cellulose is a carbohydrate
  2. Anything that contains fiber is a carbohydrate
  3. Anything that is derived from plants is a carbohydrate
  4. Anything that contains dairy or gluten is a carbohydrate

According to Science Clarified, carbohydrates are produced by plants through photosynthesis, which is the process of absorbing light energy from the sun to obtain energy. Some carbohydrates are not absorbed or digested easily, therefore, they can only be broken down by the release of gas. These ingredients include simple sugars such as lactose, fructose, and sorbitol (cheerios, PowerBar, Latte, kidney beans) and starches, and insoluble fiber (cabbage). Some foods are digestible, but some are not. According to Healthy Eating, large molecules such as proteins, carbohydrates, and fats are difficult to absorb and break down in the digestive system. Some molecules are small enough to be absorbed, such as simple sugars.


According to the food label, the percentage of the carbohydrate in the bar that is simple sugar is 31% (14g sugars/45g total carbs). The girls cannot omit all carbohydrates that are not well digested from their diet because carbohydrates are in almost everything, even in vegetables and fruits. They are necessary for our bodies to function well. These carbohydrates are used to speed digestion, such as fibers.

According to Fooduciary, the difference between simple sugars, starches, and fiber is that simple sugars are soluable. Starches, or complex carbohydrates, contain glucose and are insoluble. Fibers are much stiffer than starches and are insoluble.

Ingredients of the PowerBar that are carbohydrates are categorized in these classes:

Simple sugars: high fructose corn syrup, grape pear juice, maltodextrin, glycerin

Complex carbohydrates like starches: rice crisps, brown rice, maltodextrin, peanuts

Complex carbohydrates that contain fiber: oat bran, rice bran, peanuts, brown rice

Carbohydrates that would produce gas: everything

I learned so much from this Digestion Case Study – I was able to get a better understanding of what carbohydrates are exactly and that they are in almost everything we eat, which is vital to our health and digestion.