SACE Stage 1 Nutrition Practice Exam 2025 - Free Nutrition Exam Questions and Study Guide

The distinction between simple and complex carbohydrates primarily lies in their chemical structure, which is captured in the choice that notes simple carbohydrates are made of one or two sugar units, while complex carbohydrates consist of long chains of sugar units.

Simple carbohydrates, also known as simple sugars, generally include monosaccharides like glucose and fructose, as well as disaccharides like sucrose (table sugar) and lactose (milk sugar). Their simplicity in structure allows for rapid digestion and absorption in the body, leading to a quick surge in blood glucose levels.

In contrast, complex carbohydrates are composed of oligosaccharides and polysaccharides which consist of three or more sugar units linked together. These complex forms are typically found in foods such as whole grains, legumes, and starchy vegetables. Due to their larger molecular structure, complex carbohydrates are digested more slowly, providing a more gradual release of glucose into the bloodstream and a sustained source of energy.

This fundamental difference in structure and digestion impacts how these carbohydrates affect energy levels, satiety, and nutritional value, making it an essential distinction in understanding dietary choices.