2.3 Carbohydrates and Lipids

Evaluating claims—health claims made about lipids in diets need to be assessed. (5.2) (IBO; 39)

This NOS links nicely to to syllabus knowledge statements:

  1. Unsaturated fatty acids can be cis or trans isomers. (IBO; 39)

  2. Application: Scientific evidence for health risks of trans fats and saturated fatty acids. (IBO; 39)

  3. Application: Evaluation of evidence and the methods used to obtain the evidence for health claims made about lipids. (IBO; 39)

The concept of evaluating claims also lends itself to TOK.  Thus it is possible to teach necessary content, the NOS and provide TOK integration, all in the one lesson.  This is the best way, in my opinion, to incorporate the NOS (or TOK for that matter)- not as “additional content” but complementary to the learning that is already going on.

The first lesson involves covering the understandings: the molecular structure of fatty acids, the differences between saturated and unsaturated FAs and the difference between cis and trans unsaturated FAs.  This covers the content needed.  In our next lesson, the students are placed in groups and have one of the following four articles allocated to them:

We should ban Trans Fats – The Guardian

Dairy Products Don’t Cause Heart Disease– The Guardian

Are Fats Bad? – New York Times

Butter is Back – New York Times

As part of their reading, the students are asked to identify the First Order Knowledge Claims made in the article.  These are claims about knowledge within specific subject areas – for instance, Trans fats increase the risk of heart disease.

The students then share their knowledge claims on the board, using the Sustainability Compass (Compass Education). The board is divided into the four compass points (N, E, S, W), representing the four key dimensions of sustainability: NatureEconomySociety, and Well-being. This adds another layer to the discussion by having the students incorporate systems thinking – environmental effects of industrial animal farming, econmoic impacts of chronic health problems, the personal impacts of diet choices and lifestyles etc.

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The Sustainability Compass (Compass Education

The next part is, as a class, to select 3-5 of these First Order Knowledge Claims and identify the TOK concepts and vocabulary that match them best and to then develop them into Second Order Knowledge Claims.  These are the focus of TOK – claims about the nature of knowledge.  Students must be able to distinguish between first and second order claims as a central part of their TOK course. The final task is to develop the second order knowledge claims into appropriate knowledge questions (open-ended, general and about knowledge) – which are cornerstone of the TOK presentation and essay.

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Ideally, we do this in one 85-minute lesson, though if you set the reading for homework it would be possible to complete this in a shorter period.

Thanks to Camille Garewal (@CDolmont) for pictures and inspiration for this post.


IBO. Biology Guide: First Assessment 2016. IBO, 2014.

“Compass and Accelerator Tools.” Compass Education, AtKisson, 10 Aug. 2017, http://www.compasseducation.org/resources/compass-and-accelerator/.

IBO. Theory of Knowledge Guide: First Assessment 2015. IBO, 2013.

“Sustainability Compass.” Accelerator Pro, AtKisson, 2017, atkisson.com/tools/.