Carbs (nutrition)

Carbohydrates: Structure, Function, and Nutrition

Learning Objectives

This section outlines the key learning goals for understanding carbohydrates in human nutrition.

• Identify the types of carbohydrates (monosaccharides, disaccharides, polysaccharides), their chemical structures, and major food sources.

• Describe the process of carbohydrate digestion and absorption.

• Explain how the body maintains blood glucose concentration and the consequences of imbalances.

• Discuss the health impacts of added sugars.

• Summarize the health benefits and recommendations for starches and fibers.

• Evaluate scientific evidence regarding controversies about carbohydrates and their caloric value.

The Importance of Carbohydrates

What Are Carbohydrates?

Carbohydrates are a major class of macronutrients essential for human health and are found primarily in plant-based foods.

• Sources: Vegetables, fruits, nuts, legumes, and grains are rich in carbohydrates.

• Dietary Staples: Carbohydrate-based foods are staple foods in many cultures worldwide.

• Preferred Energy Source: Carbohydrates, especially in the form of glucose, are the most desirable and efficient energy source for the body.

• Physiological Role: The brain and red blood cells rely almost exclusively on glucose for energy.

Definition: Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen, typically with the general formula $C_n(H_2O)_n$.

Examples and Applications

• Glucose is the primary fuel for the brain and muscles during activity.

• Starch in grains and tubers provides sustained energy.

• Dietary fiber from plant foods supports digestive health.

Additional info: Carbohydrates are also involved in cell signaling and structural functions (e.g., cellulose in plants).