The Basic Science of Carbohydrates
What are carbohydrates, and how do they increase our hunger and cause us to become overweight? Carbohydrate is the term for a wide range of molecules that are often categorized as starch, sugar or fiber. They are usually derived from plant leaves, roots, seeds or fruit. A few exceptions to this rule are honey and the sugar found in milk.
Sugar is a small molecule that comes in many forms (glucose, fructose, sucrose, lactose) and all types of sugars can eventually be stored as fat or burned as a source of fuel for our cells.
Starch is a term for a molecule that is a long chain of smaller sugar molecules hooked together to form a single long molecule. Starches are digested in our intestinal tract into individual sugar molecules and then absorbed into our blood stream.
Complex carbohydrate is another term often used to describe starches. Think of starches and complex carbohydrates as a time-released form of sugar or energy for the body.
Fiber is a term given to carbohydrates that cannot be digested by humans. A simple example of this would be the fiber in common grass. Now we wouldn’t think of eating this for dinner because we do not have the proper digestive enzymes to break this down into the simple sugar molecules. Other animals, such as cattle, can digest common grass, convert it into sugar, absorb the sugar and burn it as a source of energy.
All the vegetables and grains (wheat, oats, etc) humans eat contain varying amounts of undigestible fiber. Unfortunately, modern processing of our vegetables and grains often destroys the fiber contained within these foods causing them to become less healthy for us. These are often referred to as processed (or fiber-less) carbohydrates.
Processed carbohydrates refers to starches and sugars that have been manipulated through manufacturing processes that destroys the natural fiber that comes with the natural form of many foods.
Natural Form / Processed Form
Fruit / Fruit Juice
Corn / Tortilla Chips
Whole Grain Flour / Processed Flour Products
Cow’s Milk / Yogurt
Steel-Cut Oats / Instant Oatmeal
The lower fiber content allows the byproduct of carbohydrate metabolism, sugar, to be more rapidly absorbed through the intestinal tract. The rapid absorption results in higher spikes of blood sugar and insulin. The higher spikes in insulin from these processed carbohydrates lead to a false and unneeded increase in our sense of hunger. The increased hunger leads us to eat more and gain more weight.
Look forward to future posts of how processed carbohydrates affect your hunger!