How do I identify ‘good’ and ‘bad’ food?
In this unit we focus on the experimental processes used to identify ‘good’ and ‘bad’ foods, and how these experiments are translated to the public. We will critically evaluate some examples of nutrition research to understand how the design limitations of nutritional research contribute to confusion behind some nutritional messages and the ever-changing messages about ‘good’ and ‘bad’ foods.
What is nutrition science?
This lesson is unique from the other lessons in this module because it asks student to consider a key concept about the nature of research – asking questions. Students will watch a short video clip of a scientist describing what science means to him, then they will practice asking scientific questions, a pivotal part to the scientific method. Finally, students will be briefly introduced to the types of studies used to research questions in nutrition, which will be focus of tomorrow’s lesson.
|– Explain the role of asking questions in guiding science.
– Form a scientific question.
– Become familiar with the scientific method, and be able to explain where questioning fits.
|Ask scientific questions about nutrition or metabolic diseases.
– Activity worksheet
– HW worksheet
|Complete the homework worksheet.
“Good” vs “bad” food – How do we tell?
In this lesson we further explore the concept that how a research study is conducted plays a significant role in the conclusions that can be drawn from the data. The lesson begins by discussing types of studies and their limitations. Next we focus on types of bias and confounding variables that are commonly associated with these studies. This leads the students to the idea that our understanding of ‘good’ and ‘bad’ food is constantly changing, in part because of the challenges of designing studies using human subjects, emphasizing how important it is to be critical of nutritional information.
|– Describe the main types of nutritional studies.
– Compare and contrast the limitations of each type of study.
– Identify bias and confounding variables.
|Lecture/discussion about different types of studies, and their limitations, bias and confounding variables.
|Students will select a question from their Lesson 4.1 homework and design a study to answer that question.
Why are there contradictory messages about ‘good’ and ‘bad’ foods?
In this lesson (which may need to be divided into two), we will examine claims that both the Atkins diet and the Mediterranean diet prevent heart disease. Since these diets are essentially nutritionally opposite, the idea that they could both be protective against heart disease is counter intuitive. Here we will explore the evidence supporting these claims.
|– Explain how experimental design produces limitations in the ability to interpret results.
– Explain that if a study does not prove causation the data may support more than one conclusion.
– Explain how limitations in experimental design account for the fluid nature of nutritional information provided by the media.
|Worksheet: Case study of diets.
– Case study worksheet
– Teacher’s guide
|Complete the worksheet.
Seeing through the static – How do we identify correlations in data?
In this lesson students will use results from the Framingham Heart Study to investigate two factors correlated with cardiovascular disease (CVD): HDL and LDL cholesterol, and BMI. The activity name, ‘Seeing through the static’, has been chosen to illustrate one of the main points of the lesson: real data from observational studies is complex and difficult to interpret because numerous variables impact outcomes, and we may not understand the importance of each variable.
|– Find a describe the meaning of the correlations in scientific data.
– Explain why large population studies may result in unclear data.
|Use the worksheet to explore what correlations look like in real scientific data
– Activity worksheet
|Complete the in-class worksheet.
Treating obesity with behavior modification
In the last Unit, students learned about the importance of the reward pathway in regulating our desire to eat. They also learned that treating obesity requires attention to psychological aspects of eating as well as physiological ones. Today we will investigate a study that examined whether treating obesity with diet and exercise would be improved if the treatment was combined with cognitive behavioral therapies that have been effective for treating eating disorders (binge eating). Students will use their expertise in critiquing study design and data to evaluate the results.
|– Dissect and explain the main hypothesis and methods used in the primary paper.
– Describe the results in the primary paper.
– Identify alternative explanations for the results found in the paper.
|Work in groups to critique the study using the worksheet.
– Primary paper
– Activity worksheet
|Use the worksheet as a guide to design a study for the treatment of obesity based on the reward pathway.
Teacher Prep: Unit 4 Lesson Overview Videos
In the YouTube embed below, click the order listing in the upper right to toggle the display for the full playlist.