Refined vs. Unrefined Carbohydrates
Which Carbs are Essential to Your Diet and Why You Need Them
Sep 2, 2009
In the past several years, an onslaught of media touting the dangers of excessive carbohydrate consumption has led many Americans to question the role of carbohydrates in the diet. Will carbs make me fat? Which are bad carbs, and for that matter, which are good carbs?
The fact is that excessive consumption of any kind of calorie has contributed to the widening of the American waistband. Admittedly, however, an overwhelming proportion of the American diet now comes from processed food, food that largely comprises refined carbohydrates. And thanks in part to misdirection by food marketers, the public is more confused than ever about what constitutes a healthy diet. Are carbs really evil, and if not, which kinds should we be eating?
How Carbohydrates Function in the Body
To understand the effects of processed, or refined, carbohydrates on the body, first we must understand what carbohydrates are. Of the three macronutrients that provide calories to the human body---carbs, fat, and protein---carbohydrates are the body’s most immediate energy source. Any time our bodies do work, whether through physical exercise or cognitive functions like taking a test, we burn carbohydrates for fuel. Stored carbohydrates, found in skeletal muscle and liver tissue, are known as glycogen until broken down for energy. If these carb calories don’t get used, they’ll typically be stored as body fat.
The bottom line is that we need carbohydrates. We need them to give us energy to go about daily tasks, we need them to get us through a tough workout, and we need them for our brains and nervous system to function. But we also need to know which kinds of carbs are the most nutritionally dense and therefore the best for us. Keep in mind that no kind of carbohydrate is fundamentally dangerous or “bad” for you; like many things, it’s excessive consumption that should be avoided.
The Problem with Refined Carbohydrates
Carbohydrates, which are really just sugars or chains of sugars, are a large component of plant foods, namely seed foods like wheat, corn, oats, and rice. They’re also found in fruits (in simple sugar form) and in smaller amounts in vegetables (which are largely fiber and water and therefore have a low caloric content). Carbohydrates become refined when these foods are processed by humans, often to reduce production costs and to extend their shelf life.
Here’s an explanation of refinement, using wheat flour as an example: refining, or milling, flour involves removing the bran (which contains most of the fiber) and the germ (which contains protein, important B vitamins like folic acid, and omega-3 fatty acids) from the wheat kernel, and then grinding the remaining endosperm (which contains mostly starch, a polysaccharide carbohydrate) into a fine white flour. Translation: refining removes many essential nutrients from the wheat, thus giving us calories (energy) without much nutritional density. The result of roughly 130 years of refining in America is a diet that’s calorie dense but lacking in the things our bodies really need: fiber, protein, vitamins, and unsaturated fats.
According to a 2000 USDA Economic Research Service report entitled “Major Trends in U.S. Food Supply, 1909-99,” the percentage of calories from (simple) sugars in our diet has jumped from 13 percent (in 1909) to 20 percent, and the percent of calories from other carbohydrates, many of which are refined, is up to 40 percent. We’re getting these carbs from sugary beverages like soda and juice, from white breads, rices, and pastas, from French fries, and from various processed sweets like cookies, muffins, and doughnuts---foods that hardly epitomize a balanced, healthful diet.
Where, then should we be getting the complex, unrefined carbs that our bodies need?
Sources of Good Carbohydrates
Anywhere from 40 to 60 percent of the calories in a balanced diet can come from carbohydrates, depending on your nutritional needs. What’s important is to consume carbohydrates that are rich in vitamins, minerals, and fiber, if not also unsaturated fat and protein. Here are some excellent sources to consider:
- Vegetables can be consumed in nearly unlimited quantities for their high nutritional content and low calorie yield. Include a mixture of veggies from green, leafy sources like spinach, beta-carotene-rich sources like carrots and bell peppers, root vegetables like radishes and potatoes, and sulfuric veggies like garlic and onion.
- Fruits, though they contain simple sugars, tend to be low-calorie, fiber-rich, and laden with vitamins and minerals. Plus, they’re about as natural as it gets; just make sure to consume them in whole form (not in juices) and aim for 2-3 servings per day.
- Whole-grain foods like oatmeal, bran, buckwheat, barley, and quinoa are can’t miss sources of healthy carbohydrates as they’re loaded with B vitamins and fiber. Look for cereals rich in these natural ingredients that don’t contain too much added sugar.
- Whole-wheat breads, pastas, and brown rice are also fine as long as you watch the portion sizes. A serving of rice or pasta is one cup, and a single slice of bread is a serving.
- Legumes like soy, lentils, and beans are incredibly fiber- and protein-dense, so you can eat large amounts of these foods as well.
Source: Pollan, Michael. In Defense of Food: an Eater’s Manifesto. New York: Penguin Books, 2009.
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