Teaching Sequence

Work through this resource material in the following sequence:

15 minutes	Part B: Activating Prior Knowledge - Optional
35 minutes	Part C: Investigating ‘Lite’ Foods
10 minutes	Reflection

Part A: 'Lite' Foods

This first section introduces the topic of ‘lite’ foods and sets up the investigation for students. ‘Lite’ foods are any sort of food (or drink) that are marketed as healthier than their regular counterparts. They might use terms such as ‘low-fat’, ‘diet’, ‘light’, or, of course, ‘lite’.

Step 1.

Start by asking students to brainstorm about the meaning of ‘lite’ foods.

Most students probably have a general idea that ‘lite’ foods are meant to be healthier, and some may know that it involves lower amounts of fat. However, the technical definition, across both Australia and New Zealand, is actually very specific.

In order for a food product to be labelled ‘low fat’, it must contain less than 3g of fat per 100g of food. A drink must contain less than 1.5g of fat per 100g.

Alternately, to be labelled ‘reduced fat’, a food product must have a 25% reduction in fat compared to the regular product, as well as 3g less fat per 100g.

(You can find these figures referenced in both Australia (here: https://daa.asn.au/smart-eating-for-you/smart-eating-fast-facts/food-labels/what-does-low-fat-mean/) and New Zealand (here: https://www.fuelled4life.org.nz/tips/what-does-low-fat-and-reduced-fat-mean).

Step 2.

Play a guessing game with your class to help bring them to the definition of ‘low fat’ and ‘reduced fat’.

Start by explaining that ‘low fat’ means ‘less than a certain amount of fat per 100g of food.’ Ask one student to guess what that amount might be (for instance, they might say 20g). Write their guess on the board, and then ask all of your students to vote on whether they think the real number is higher, lower, or exactly what that student has guessed. They can display their votes by putting their thumbs up, down, or sideways, respectively. After the vote, reveal whether the real number is higher or lower, and then ask another student to make a second guess. Write that guess on the board as well, and repeat until students have identified the correct number.

This activity gives students an opportunity to practise estimating. For instance, you could write the numbers along a number line, giving a visual representation of scale. Then, if the first student were to guess, say, 40g, the next student might be encouraged to guess 20g as a halfway point between 40g and 0g. The visual representation of scale may help students to identify the value of picking the halfway point each time as the quickest way to drill down to the correct answer.

You may also wish to repeat the activity for the definition of ‘reduced fat’, perhaps asking students to identify the necessary percentage reduction, the 3g reduction, or both.

Once you have identified the definitions of ‘low fat’ and ‘reduced fat’, you can begin your investigation into the nutritional values of different ‘low fat’ or ‘reduced fat’ foods.

Part B: Activating Prior Knowledge - Optional

If you have not completed any of the earlier SugarByHalf Math lessons, consider using this introductory section to teach students about the Nutrition Information Panel (NIP). The information in the Teacher Content Information section (above) may aid your teaching here. Alternately, we recommend the introductory lesson in this unit, Portion Problems, which has a section on teaching students to understand the NIP.

Step 1.

Run a brief review on the Nutrition Information Panel and what each of its parts means.

Step 2.

Students complete the student worksheet, where they are asked to label each section of the NIP and outline what each section means.

Depending on time allowance, you may wish to encourage students to explore the whole NIP. Otherwise, the most important sections for the rest of this lesson will be the ‘Average Quantity per 100g’ column, and the ‘fat’ and ‘sugar’ rows, so ensure that students have a strong understanding of those sections before continuing.

Part C: Investigating 'Lite' Foods

In this section, students investigate ‘lite’ food, checking whether the fat content is as low as expected for low-fat or reduced fat products, and checking whether any other qualities increase. Students specifically check whether the low-fat or reduced fat products have increased amounts of sugar.

Step 1.

Provide a selection of packaged foods along with their reduced fat, fat free, or lite counterparts.

There are a number of ways you could collect this packaging: for instance, you could ask students to bring in different versions, if they have any. You may also choose to bring in some products yourself; alternately, many major supermarket chains include NIP information for different products on their website: you may wish to collate information from those products into a slideshow or handout for students.

Although we wouldn’t point towards any one specific product or company, in a more general sense this activity might work well with dairy products such as yoghurt or mayonnaise. Some salad dressings also illustrate the point forcefully. As in previous lessons, a little research will go a long way.

It will also be important to compare like with like here: for instance, comparing a low-fat version of a product with a regular version of some other product will not yield useful results. Some of the variance here will be due to the very typical variance between individual product lines. Again, this is one reason why research before the lesson is important - if students are to do their own investigation, you may need to guide them towards a list of products that you have already identified.

Step 2.

Once students have identified their food pairing, whether through research or by receiving supplied packaging, the first step is to compare the relative fat content.

Students should use the ‘Ave Qty per 100g’ column to compare the different amounts of fat. You may wish to lead a discussion here on why we use the ‘Ave Qty per 100g’ column for this comparison, and not the ‘Ave Qty per Serving’ column. Although we might expect the serving size between a normal product and its low-fat version to be more or less the same, we can’t be sure. The ‘per 100g’ column gives us a more reliable and straightforward point of comparison across products. It also allows us to think more easily in terms of percentages

Using the ‘per 100g’ column, students should compare the relative fat content of their two products and determine whether the lower fat version fits within the relative guidelines.

Remember: in order for a food product to be labelled ‘low fat’, it must contain less than 3g of fat per 100g of food. A drink must contain less than 1.5g of fat per 100g.

Alternately, to be labelled ‘reduced fat’, a food product must have a 25% reduction in fat compared to the regular product, as well as 3g less fat per 100g.

Be sure that students distinguish between ‘low fat’ and ‘reduced fat’ in making their comparison. Further, if students are examining a product with vaguer, more general low-fat claims (for instance, a ‘lite’ version of a normal product), then they should determine the fat difference and decide whether the product could legally fit into the ‘low fat’ or ‘reduced fat’ categories. Any product that fails this test might provide further opportunity for teaching: what does it mean that this product is marketed as ‘lite’, but fails to provide any meaningful reduction in fat content? What does it suggest about advertising terms like ‘lite’? The SugarByHalf English lessons may provide further support for teaching in this direction.

Step 3.

Once students have determined the relative fat content of their products, they should examine whether any other listings change between the two products. Direct special attention to the sugar row - in some ‘lite’ or low-fat products, the reduction in fat corresponds to a raise in the amount of sugar used. Again, students should use the ‘per 100g’ column to make their comparison.

You might want to ask students further questions about any significant changes from one product to another. For example:

If the sugar content does go up, how much does it go up by?
Is that increase a significant amount?

The conversation here can again move towards the English end of the spectrum. If the sugar content goes up, how might that affect our perception of the healthy ‘low-fat’ marketing? There are wider lessons here for students about how marketing works: a reduction in one area doesn’t guarantee anything about the rest of the product, and so it doesn’t necessarily translate into a healthier product overall. It’s worth being critical of things that are marketed as healthy; how something is marketed is not necessarily a guarantee of its real nutritional value. Some of the products discussed might not have even been that unhealthy in the first place. When companies sell, for instance, low-fat milk, they’re marketing it on the claim that it’s a ‘healthy’ alternative to normal milk, which might then seem like a less healthy option by comparison - even though it might be generally fine! Plus, some studies have shown that foods marketed as ‘low-fat’ sometimes have other issues, such as an increased sugar content - which is just as troubling, from the perspective of weight loss and obesity. (For instance, see this open-access journal article, which compares the sugar content of low-fat and regular foods.) The central takeaway is that it’s always worth being smart in how we think about and absorb advertising messages.

Reflection

Students can discuss the following questions in groups of two or three:

Did the variations in sugar content in reduced fat products surprise you?
How did this activity make you feel about some of the food that you consume?
What would you like to share?
Where to next?
How are you going to get there?

Teacher Reflection

Take this opportunity to reflect on your own teaching:

What did you learn about your teaching today?
What worked well?
What didn't work so well?
What would you share?
Where to next?
How are you going to get there?

SugarByHalf - Investigating 'Lite' Foods

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