Carbohydrates (often referred to as “carbs”) are the source of much discussion and debate in the media these days. The conflicting information can be very confusing. Some sources suggest that carbs are “good” and provide a lot of healthy benefits. Others suggest that carbs are “bad” and contribute to diabetes, obesity and elevated triglycerides. But what is the right information? And more importantly, what should I eat? The answer is that carbohydrates are an essential part of a healthy diet but it is important to understand how to choose them wisely.
Carbohydrates are a type of macronutrient (along with protein and fat) that provides energy for the body to function. But all carbohydrates are not created equal, so to speak. Carbohydrates are either simple or complex based on their chemical structure.
SIMPLE CARBOHYDRATES consist of very basic sugars (single monosaccharide and disaccharide units) that are easily and quickly digested and offer little nutritional value. These simple sugars occur naturally in some foods such as fruits and vegetables but are packaged by nature with vitamins, minerals, fiber and phytochemicals—all of which are beneficial. Simple sugars are often added to foods and beverages during processing (think candy, soda, baked goods and convenience foods).
Reading the ingredient list on a processed food’s label can tell you if the product contains added sugars. When looking at ingredient lists keep in mind that the line for “sugars” includes both added and natural sugars in the product. The ingredients are listed in descending order of predominance by weight, which means that the ingredient that weighs the most is listed first. Foods with added simple sugars generally have fewer nutrients than foods with naturally occurring simple sugars. In other words, simple carbohydrates or processed foods are more often “empty calories”.
Some examples of simple sugars to look for on the nutrition label include:
- Brown sugar
- Corn sweetener
- Corn syrup
- High fructose corn syrup
- Fruit juice concentrate
- Invert sugar
- Malt sugar
- Raw sugar
- Sugar molecules ending in “ose”: dextrose, fructose, glucose, lactose, maltose, sucrose
Refined foods such as white flour and white rice have had much of their nutrients removed during the refining process. Essentially they have been reduced from a complex carbohydrate to a simple carbohydrate. In many cases, the refiners add some of the nutrients back to the food. These foods are referred to as “enriched”.
Should I eat simple sugars?
Unfortunately, consuming large amounts of simple sugars may take the place of nutrient dense foods like fruits, vegetables, nuts, seeds, legumes and whole grains. You should be mindful that simple sugars are often found in products that are calorie dense such as sugary sodas, sweet tea, baked goods and other sweet treats. Eating more carbohydrates (glucose) than your body requires for energy can lead to health problems such as obesity, elevated triglyceride levels heart disease, diabetes and more. Simple sugars can be part of a healthy diet in moderate amounts on special occasions.
COMPLEX CARBOHYDRATES are starches and fiber, which contain longer chains of 3 or more sugars (oligosaccharides or polysaccharides) and must be broken down through digestion before the body can utilize the individual glucose molecules for energy.
Starch is the storage form of carbohydrates in plants and is a digestible long chain of glucose units (polysaccharide). It is generally found in the roots or tubers, grains and seeds of plants where it provides the plant with the energy for growth and production. Legumes and beans also contain starch. Because starch can be digested, the nutrients can be absorbed into the body. Starches are high quality carbohydrates but are calorie dense and can raise blood sugar levels more than non-starchy vegetables.
Fiber is a long chain of glucose units (polysaccharide) that constitutes the chief parts of plant cell walls; human enzymes cannot digest it. It is what my grandma used to refer to as “roughage”. Since they cannot be digested, they cannot be absorbed into the body.
There are two types of fiber: soluble and insoluble. Both are important for optimal health and offer benefits for digestion, blood sugar control, obesity, heart disease, colon cancer and more.
Soluble fiber dissolves in water and forms a gel, which delays stomach emptying and slows the digestive process. This may prevent blood sugar peaks and valleys and have a beneficial impact on insulin sensitivity. Soluble fibers can also lower LDL (bad) cholesterol by interfering with the absorption of dietary cholesterol. The sense of fullness provided by delayed stomach emptying can be helpful with weight loss as well. Bacteria in the large intestine can digest some of these soluble fibers (known as resistant starches) and turn it into beneficial short chain fatty acids which in turn fuel the cells of the colon lining and help to maintain a healthy gut.
Some sources of soluble fiber include: oatmeal, oat bran, lentils, most fruit, nuts, flaxseeds, dried beans, dried peas, psyllium, cucumbers, celery and carrots.
Insoluble fiber does not dissolve in water and cannot be used by gut bacteria but does provide other benefits. It also bulks the stool helping to prevent constipation. Because it does not dissolve in water, it passes through the GI tract relatively intact speeding up the passage of food waste through the gut reducing the contact time with potential toxins in the colon.
Some sources of insoluble fiber include: whole wheat, whole grains, wheat bran, corn bran, seeds, nuts, barley, brown rice, bulgur, zucchini, celery, broccoli, cabbage, onion, tomatoes, carrots, cucumbers, raisins, grapes, root vegetable skins.
Many foods contain both soluble and insoluble fiber. Insoluble fiber is found in the outer skins of many legumes, vegetable and fruit skins while their insides are actually rich in soluble fiber.
How many carbohydrates do I need to eat each day?
The Dietary Guidelines for Americans recommends that carbohydrates make up 45%-65% of your total daily calories. So, if you eat 2,000 calories per day, between 900 and 1300 calories should be from carbohydrates. That translates into 225-325 grams of carbohydrate. The carbohydrate content of packaged foods is available on the nutrition label. Websites like Calorieking.com or similar will be helpful in providing information about fresh foods.
How much fiber do I need?
Women need 25 grams of fiber per day, and men need 38 grams per day, according to the Institute of Medicine. You don’t need to consider the type of fiber unless you are seeking a specific health benefit—such as insoluble fiber to aid constipation. Generally variety is best because you are more likely to get other nutrients as well. It is important to drink adequate fluids as you increase your fiber intake.
TAKE AWAY MESSAGE:
Get the many health benefits of “good” (complex) carbohydrates by choosing a diet rich in complex carbohydrates like fruits, vegetables, nuts, seeds, dried beans and peas, and whole grains.
Minimize the health risks associated with “bad” (simple) carbohydrates by eating refined and processed foods less frequently. Eat foods with added simple sugars less frequently. Save sugary beverages and sweetened treats for special occasions.
How have you tried to include more complex carbohydrates in your diet? Try some of my recipes, like this delicious Black Bean Sweet Potato Chili.