Carbohydrates are one of three classes of food called macronutrients (the other two are fats and protein). The term “carbohydrate” is a big umbrella, including everything from table sugar to cauliflower. The basic unit of a carbohydrate is a monosaccharide or simple sugar (such as glucose or fructose), but these simple sugars can be linked together in infinite ways, and will have very different effects on the body depending on their arrangement.
The body can obtain everything it needs to survive from protein, fats and the right kind of dietary carbohydrates (or good carbs), like vegetables, which offer many valuable components such as antioxidants, fiber, vitamins and minerals.
There are three main types of carbohydrate in food. They are:
- Starches (also known as complex carbohydrates)
You’ll also hear terms like naturally occurring sugar, added sugar, low-calorie sweeteners, sugar alcohols, reduced-calorie sweeteners, processed grains, enriched grains, complex carbohydrate, sweets, refined grains and whole grains.
Starches are long complex chains of simple sugars. This is why they are often called “complex carbohydrates”. It was once thought that complex carbohydrates do not raise blood sugar as quickly or as much as sugars, but now we know that some starches are actually more glycemic than some sugars. In this sense, they are not “complex” for very long at all. People who are sensitive to sugar should avoid most starchy foods as well, since most starchy foods are rapidly broken down into sugar.
Foods high in starch include:
- Starchy vegetables like peas, corn, lima beans and potatoes.
- Dried beans, lentils and peas such as pinto beans, kidney beans, black eyed peas and split peas.
- Grains like oats, barley and rice. (The majority of grain products in the US are made from wheat flour. These include pasta, bread and crackers but the variety is expanding to include other grains as well.)
Sugar is another type of carbohydrate. You may also hear sugar referred to as simple or fast-acting carbohydrate.
There are two main types of sugar:
- Naturally occurring sugars such as those in milk or fruit.
- Added sugars such as those added during processing such as fruit canned in heavy syrup or sugar added to make a cookie.
On the nutrition facts label, the number of sugar grams includes both added and natural sugars.
There are many different names for sugar. Examples of common names are table sugar, brown sugar, molasses, honey, beet sugar, cane sugar, confectioner’s sugar, powdered sugar, raw sugar, turbinado, maple syrup, high-fructose corn syrup, agave nectar and sugar cane syrup.
You may also see table sugar listed by its chemical name, sucrose. Fruit sugar is also known as fructose and the sugar in milk is called lactose. You can recognize other sugars on labels because their chemical names also end in “-ose.” For example glucose (also called dextrose), fructose (also called levulose), lactose and maltose.
Fiber comes from plant foods so there is no fiber in animal products such as milk, eggs, meat, poultry, and fish.
Fiber is the indigestible part of plant foods, including fruits, vegetables, whole grains, nuts and legumes. When you consume dietary fiber, most of it passes through the intestines and is not digested.
For good health, adults need to try to eat 25 to 30 grams of fiber each day. Most people do not consume nearly enough fiber in their diet, so while it is wise to aim for this goal, any increase in fiber in your diet can be beneficial. Most of us only get about half of what is recommended.
Fiber contributes to digestive health, helps to keep you regular, and helps to make you feel full and satisfied after eating. Additional health benefits, of a diet high in fiber — such as a reduction in cholesterol levels — have been suggested by some so may be an additional benefit.
Good sources of dietary fiber include:
- Beans and legumes. Think black beans, kidney beans, pintos, chick peas (garbanzos), white beans, and lentils.
- Fruits and vegetables, especially those with edible skin (for example, apples, corn and beans) and those with edible seeds (for example, berries).
- Whole grains such as:
- Whole wheat pasta
- Whole grain cereals (Look for those with three grams of dietary fiber or more per serving, including those made from whole wheat, wheat bran, and oats.)
- Whole grain breads (To be a good source of fiber, one slice of bread should have at least three grams of fiber. Another good indication: look for breads where the first ingredient is a whole grain. For example, whole wheat or oats.) Many grain products now have “double fiber” with extra fiber added.
- Nuts — try different kinds. Peanuts, walnuts and almonds are a good source of fiber and healthy fat, but watch portion sizes, because they also contain a lot of calories in a small amount.
In general, an excellent source of fiber contains five grams or more per serving, while a good source of fiber contains 2.5 – 4.9 grams per serving.
It is best to get your fiber from food rather than taking a supplement. In addition to the fiber, these foods have a wealth of nutrition, containing many important vitamins and minerals. In fact, they may contain nutrients that haven’t even been discovered yet!
It is also important that you increase your fiber intake gradually, to prevent stomach irritation, and that you increase your intake of water and other liquids, to prevent constipation.
In layman terms, Carbohydrates (or Carbs in short) can be segregated into two broad categories. Good and Bad.
Good carbs are carbs that don’t raise blood sugar too high or too quickly. The best carbohydrates (like vegetables) are found in unprocessed whole foods that are rich sources of phytochemicals – plant compounds, which protect against cancer, heart disease and other illnesses. Many phytochemicals are natural antioxidants and many are anti-inflammatory. Carbohydrates like vegetables and fruits also contain tons of important vitamins and minerals. In addition, carbohydrates are the only dietary source of fiber. Remember, a diet focused on eating plenty of good carbs is naturally low in sugar – especially processed or added sugar.
Bad carbs are highly processed carbohydrates (refined breads, cereals and pastries) that raise blood sugar too high and too quickly. These refined carbohydrates are not only higher in sugar and significantly lower in nutrients and fiber than whole foods, but they also break down more rapidly into glucose and enter your bloodstream far faster than vegetables and other good carbs. So if you eat refined carbohydrate foods, you stay on the blood sugar roller coaster ride of highs and lows.