2.1 Why do we need to eat?

Teacher & Student Materials > Feeding a Hungry Planet

Lesson Overview

Guiding question:

Why do we need to eat?

30 minutes

Purpose:

In this lesson, students will learn about the digestive system from the perspective of obtaining essential elements for life: energy and nutrients.

Overview:

Design Principles:

Student voice

Background Knowledge:

All necessary background knowledge will come from this lesson.

Common Misconceptions:

Safety:

Unit Connections:

Teacher

Teacher slides: 2.1 Why do we need to eat?

Instructional Sequence

Materials:

Teacher slides: 2.1 Why do we need to eat?

Students’ experience (slide 2)

Ask students about their fasting experiences and how they felt. This will guide them to answer why we need to eat.

Student backgrounds

Essential elements for life: energy and nutrients (slides 3)

Present the two main reasons why we need to eat:

Energy: Food provides us the energy we need to perform various bodily functions and activities. Our body breaks down the carbohydrates and fats in food to generate the energy needed for maintaining body temperature, moving muscles, and supporting the functioning of organs.
Nutrients: Food contains essential nutrients necessary for our body’s growth, maintenance, and repair. These include macronutrients such as carbohydrates, proteins, fats, and micronutrients like vitamins and minerals. Each nutrient plays a specific role in the body, supporting various functions such as cell production, immune system function, and hormone regulation.

Small-group brainstorming

Digestion system (Slide 5)

Cover the content in standards.

Whole-class discussion

Information for Planning & Teaching

Background Knowledge
Lesson Timing
Student ideas & Experiences
Science Practices
Teaching Cases

Background Knowledge:

Additional reasons why we need to eat: (1 and 2 are in main lesson text)

Metabolism: Eating regularly helps maintain a healthy metabolism. When we eat, our body breaks down food into smaller components and absorbs the nutrients. This process allows our body to regulate blood sugar levels, maintain hormone balance, and carry out various metabolic processes.
Tissue repair and growth: Our body constantly undergoes wear and tear, and eating an adequate diet provides the necessary nutrients for tissue repair and growth. Protein, in particular, is crucial for repairing damaged tissues and building new cells.
Brain function: The brain requires a constant supply of nutrients to function optimally. Glucose, derived from carbohydrates, is the brain’s primary source of energy. Additionally, certain nutrients like omega-3 fatty acids and vitamins play vital roles in brain health and cognitive function.
Overall health and well-being: Proper nutrition is essential for overall health and well-being. A balanced diet that includes a variety of foods can help prevent nutrient deficiencies, support a healthy immune system, reduce the risk of chronic diseases, and promote optimal physical and mental health.

It’s important to note that individual nutritional needs may vary based on factors such as age, sex, activity level, and health conditions. Consulting with a healthcare professional or registered dietitian can provide personalized guidance on dietary requirements.