What defines a complex carbohydrate?

A complex carbohydrate is defined primarily by its structural composition, which includes oligosaccharides and polysaccharides. Oligosaccharides are short chains of sugar molecules, typically consisting of 3 to 10 sugar units, while polysaccharides are longer chains made up of many sugar units, often hundreds or thousands. These structures result from the combination of multiple simple sugar molecules (monosaccharides) linked together.

Complex carbohydrates can be found in foods such as whole grains, legumes, and vegetables, which provide a rich source of nutrients and fiber. Unlike simple carbohydrates, which are quickly digested and can lead to rapid spikes in blood sugar, complex carbohydrates are broken down more slowly, providing a steadier release of energy. The presence of fiber in many complex carbohydrates contributes to digestive health and can help regulate blood sugar levels.

While some other choices mention characteristics related to digestion and composition, they do not accurately capture the comprehensive definition that focuses specifically on the structural elements of complex carbohydrates. Therefore, the correct answer highlights the essential components that categorize a carbohydrate as complex.