Topic Three (1.3): Unhealthy diet

Topics Icon.png Objectives

By the end of this topic you should be able to:

  • describe some health issues caused by an unhealthy diet;
  • calculate the energy requirements of different people.

Introduction Icon.png Introduction

People who suffer from malnourishment don't get enough of the nutrients they require from their diet. Malnourished people don't have to be underweight they could be overweight as their diet might be made up of the wrong proportion of nutrients and lacking in some of the important ones like vitamins and minerals.


Interact Icon.png Working through your coursebook

RECAP - Resource 1: Food for Thought PowerPoint (slide 7) Download RECAP - Resource 1: Food for Thought PowerPoint (slide 7)

VIEW - Resource 1: Food for Thought PowerPoint (slides 8-10) Download VIEW - Resource 1: Food for Thought PowerPoint (slides 8-10)

  • Read pages 8–9.
  • Remember the main vitamin deficiencies – rickets (lack of Vitamin D) and scurvy (lack of vitamin C).
  • Understand that different ages, genders and individuals have different energy requirements. 
  • The experiment below shows a way of testing to measure the energy contained within food. This is also a good experiment to watch as it shows good experimental practice and what variables are.

WATCH - Physics - Investigating the Energy Content of Food KS3 (YouTube)


Review Icon.png Review

Answer summary questions 1, 2 and 3 on page 9.

COMPLETE - B2 1.3 Interactive screen: Energy consumption (Kerboodle) Links to an external site.


Bridge Icon.png Support activity for this topic

This video covers the book content really clearly:

WATCH - Unhealthy Diet (Revision Monkey - YouTube)

Discover which foods are vital for a healthy diet. What should you be eating, how much, and why?

WATCH - Balanced Diet (Twig) [Not available on sample course]


Stretch Icon.png Extension activity for this topic

Learn more about problems with not getting a balanced diet:

WATCH - Investigating Vitamin Deficiency (Twig) [Not available on sample course]

Watch Chris and Xander burn some food with a blow torch:

WATCHOperation Ouch - Energy Machine | Science for Kids (YouTube)


Download Icon.png Check your answers

Student Book Answers - Biology 2 Chapter 1 Download Student Book Answers - Biology 2 Chapter 1