If you get cross-eyed thinking about carbohydrates, that’s understandable.
They can be, quite literally, both simple and complex. They abound in snacks that nobody would call healthy but also appear in foods considered essential to good health.
“It gets a little confusing,” says Andrew Odegaard, associate professor of epidemiology and biostatistics at the University of California, Irvine. Even experts disagree on some aspects of how carbohydrates function.
How do carbs work?
To understand how carbs work in your diet, it helps to know a few details.
“When people think of carbohydrates, what they’re thinking of can vary a lot,” says Odegaard, whose work has included studies on diet, diabetes and heart disease. But from the most basic perspective, a carbohydrate is a molecule made up of carbon, hydrogen and oxygen. When digested, carbs are converted into blood glucose, or sugar, which provide fuel for cells throughout the body.
“For most people, it’s the fundamental source of energy in their diet,” Odegaard notes.
Carbohydrates often have been classified as either “simple” – also known as “refined” – or “complex” based on how quickly the body turns them into blood glucose.
Dietary sugars, such as glucose and fructose, are simple carbs that when broken down can be a fast source of energy. Highly processed foods such as cake, candy and sugary sodas are full of simple carbs. Christopher Gardner, the Rehnborg Farquhar Professor of Medicine at Stanford University in California, noted that Americans get more than 40 percent of their calories from simple, low-quality carbs.
Complex carbs include starches, which are molecular chains of simple sugars. They have to be broken apart before the body can use them, making them a steady, longer-lasting supply of energy. Peas, beans, whole grains and vegetables are sources of complex carbs.
Fiber is also a complex carb. Your body can’t break it down, meaning it passes through the digestive system without causing spikes in blood glucose. It provides abundant health benefits along the way.
Excess blood glucose gets converted into triglycerides, a form of fat that can cause buildups within artery walls, increasing the risk of