Carbohydrates are often portrayed negatively in the media and many popular diets, but the truth is, all carbohydrates are not created equal. The right carbohydrates in our diet give us usable energy, facilitate healthy digestion, and help support a healthy weight. Too many refined carbohydrates, on the other hand, increase our risk for chronic inflammation, obesity, and type 2 diabetes. So how do we know which carbs to choose?
Functions of Carbohydrates
The main function of carbohydrates is to provide us with energy. Complex carbohydrates contain fiber, which supports gut health and helps us manage our weight and reduce cholesterol. The two types of fiber, soluble and insoluble, slow the absorption of sugar into the bloodstream and help us avoid spikes, which allows us to maintain more consistent blood glucose levels. Soluble fiber slows digestion by increasing digestive transit time, while insoluble fiber adds bulk to stool to support digestive regularity. When adding additional fiber to your diet, do it slowly to avoid gastrointestinal discomfort and remember to increase your water consumption as well.
Carbohydrates are broken down into simple sugar during digestion and absorbed into the bloodstream as glucose. Insulin then allows the glucose to enter the cells as a source of energy. Depending on your body’s needs, any unused glucose in stored in the liver or converted to fat for later use.
The recommended daily allowance for carbohydrates is 45% – 65% of your total calories. Each gram of carbohydrate contains four calories, the same as protein.
The majority of carbohydrates in a nutritious diet come from whole foods, and intake of refined grains and added sugar is limited. As with everything consider bio-individuality and keep your body and lifestyle in mind as you explore carbohydrates.
Types of Carbohydrates
There are two main categories of carbohydrates: simple and complex. These terms refer to the chemical structure of the molecules that make up the food.
Simple Carbohydrates
Simple carbohydrates are small compounds broken down quickly, providing a quick burst of energy when consumed.
Sources of simple carbohydrates included:
- Glucose
- Fruit and honey (fructose)
- Sugar (sucrose)
- Malt sugar (maltose)
- Dairy (lactose)
As a source of simple carbohydrates, fruit naturally contains sugar, but it is also a good source of fiber (unlike most processed foods with added sweeteners). Because of this, fruit doesn’t cause as sharp of a spike in blood glucose levels. In addition, fruit offers much more than just energy – it’s also a source of antioxidants, vitamins, and minerals
Complex Carbohydrates
Unlike simple carbohydrates, complex carbs are larger compounds that require more time to be break down, showing digestion and absorption and preventing extreme changes in our blood glucose levels. Complex carbohydrates include starches and fiber.
Source of complex carbohydrates include:
- Whole grains (brown rice, oats, whole wheat, barley, etc.)
- Vegetables, including starchy vegetables
- Beans/legumes
Since these foods are good sources of fiber, they also help manage weight and support cardiovascular health.
What Are Refined Carbohydrates?
Whole grains, such as brown rice, contain three main parts: bran, endosperm, and germ. The barn and germ are where most of the grain’s nutritional value lies; they contain fiber, antioxidants, vitamins, and minerals. Unfortunately, when grains and refined, these part are typically removed to increase shelf life. The endosperm, which contains carbohydrates and some protein, is typically all that remains. This means the grain no longer contains the fiber that functions to slow digestion and absorption. Because of this, refined grains ( like white flour) cause blood glucose to increase quickly.
All carbohydrates are eventually broken down into glucose to be absorbed and used either for energy readily or to be stored for when energy is needed. Foods high in simple carbohydrates, like sugar, cause our blood glucose to increase rapidly, requiring a more concerted hormonal response to clear the glucose from our bloodstream. Over time, these rapid spikes become increasingly taxing on our system; our ability to effectively manage blood sugar decreases and we become less able to produce sufficient amounts of insulin, the hormone that helps manage our blood glucose levels. The insulin that is produced is less effective. This is referred to as decreased insulin sensitivity and is a major risk factor for type 2 diabetes.