In this unit we will focus on the question: What is metabolic disease? We will first define and investigate the metabolic and physiological causes of obesity. Once we understand what obesity is, we can relate it to diseases like diabetes and atherosclerosis, which are both affected by obesity. In all the lessons, the information is connected directly to lifestyle choices that are modifiable.
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Lesson 6
Lesson 7
Lesson 1
What is obesity and how does BMI relate?
This lesson begins by presenting data that shows the rise in obesity levels in the United States over the past thirty years. Next we raise the question of how obesity is measured and students then critique the different methods to measure body composition and to define obesity. In the end of the lesson we transition to exploring the causes of obesity.
Objectives
– Define body composition and obesity. – List some of the comorbidities of obesity.
Activities
Worksheet: Compare two characters that have similar BMIs but very different ratios of body fat.
In this lesson we will explore how exercise and body composition relate to metabolic rate. The concepts we will cover include the idea that ‘fast’ and ‘slow’ metabolism is largely a consequence of lean muscle mass. We will also explore other factors that may contribute to metabolic rate, such as efficiency of food absorption.
Objectives
– Explain how the following factors contribute to basal metabolic rate: – Activity levels – Muscle mass – Efficiency of caloric absorption
Activities
Worksheet: Calculating basal metabolic rate.
Materials
Printed Materials: – Activity worksheet
Homework
Complete worksheet and write a paragraph describing why it can be challenging for some people to regulate their weight.
Lesson 3
What makes us feel hungry or full?
In this lesson we will explore the signals that regulate sensations of hunger and satiation, and we will spend the next two lessons relating these signals to appetite and obesity. We will also consider the possibility that overeating is a disease, similar to drug addiction, because the same reward pathways in the brain that drive substance abuse also provide the powerful signals that drive us to eat.
Objectives
– Explain hunger and satiety signals. – Explain how the hypothalamus regulates hunger. – Compare and contrast drug and food addiction.
Activities
Watch a clip from 60 Minutes: “Hooked: Why bad habits are hard to break”.
Read the primary paper: “Long-Term Persistence of Hormonal Adaptations to Weight Loss”; use Lesson 3.5 worksheet as a reading guide.
Lesson 4
Can you become addicted to food?
In this lesson we will examine yet another complicating factor that can thwart intentions to lose weight and maintain weight loss – the similarities between how our brain behaves when confronted with food and how it behaves when confronted with drugs of abuse. The realization that there are many commonalities between the addicted brain and the obese brain is a recent one, and it has significant implications for treatments of obesity.
Objectives
– Describe the dopamine reward pathway. – Compare and contrast drug and food addiction. – Explain how knowledge about drug addiction might apply to dieting.
Activities
Jigsaw linking specific elements of the reward pathway that are activated during drug addiction with obesity.
Continue reading the primary paper: “Long-Term Persistence of Hormonal Adaptations to Weight Loss”
Lesson 5
Homeostasis gone awry — How does the satiety pathway relate to obesity?
In the last lesson we explored how the body regulates the sensations of hunger and satiety. In this lesson we will work our way through a primary research paper that shows how changing diet and lifestyle may not rebalance homeostasis signals. This data has important implications for people attempting to lose weight. Spending class time to work through a primary research paper will prepare students for their final project. Note: this may take two class periods depending on how much the students were able to complete as homework.
Objectives
– Explain hunger and satiety signals. – Describe how overstimulation of the reward pathway leads to obesity. – Analyze a scientific article
Activities
Case study/Jigsaw: “Long-Term Persistence of Hormonal Adaptations to Weight Loss”
In the last few lessons we have explored how the brain regulates overeating. We have also seen that hunger signals may not adapt after weight loss, contributing to the weight regain that often occurs when people have lost weight by dieting. Here we further explore the consequences of obesity by focusing on diabetes and atherosclerosis. After reviewing these diseases in the activity we will return to the question: how does obesity lead to disease? It’s a question that has no clear answer and is a current area of research.
Objectives
– Describe the mechanisms of type 2 diabetes, type 1 diabetes and atherosclerosis. – Explain how unhealthy adipose may contribute to disease.
Activities
Lesson 3.6 worksheet and teach-back.
Materials
Printed Materials: – Activity worksheet
Homework
Complete the Lesson 3.6 worksheet.
Lesson 7
The metabolic mystery patient lab
We have now learned about the mechanism and symptoms of diabetes. In this lesson, students will spend the entire class period measuring “blood” glucose concentrations from a patient. Students will use their knowledge of glucose homeostasis to determine what causes fluxes in blood glucose throughout a day, and will diagnose the patient with diabetes. Students are then asked to make a recommendation to treat the disease.
Objectives
Explain the primary cause of abnormal blood glucose concentrations.
