Thursday, January 30, 2014

Understanding Nutrition


Uni doesn't start for a couple of weeks but I've read Chapter One of my Introduction to Nutrition textbook and since this is mainly a health/weight-loss I though you might be interested in what I am learning.

Understanding Nutrition, Whitney et al, Cengage Learning, 2011

Chapter One was an introduction and overview and didn't really contain new information for me, but it was reassuring to have some familiar concepts reinforced (as opposed to my Biology textbook which was nearly all new stuff).

It went through some reasons why people make food choices; including taste, habit and social/cultural conventions among others. It went on to list the macro and micro nutrients (proteins, fats, vitamins etc) and talked about kilojoules/calories. In Australia we officially use kilojoules, but a lot of people including myself think in terms of calories so I will need to get used to kilojoules (1 kilojoule = 4.2 calories).

Here is a fun fact, what most people call calories are actually kilocalories. The name has been shortened which is very inaccurate - imagine if we started calling kilometres "metres" because it is a shorter word! Not the same thing at all.

Then there was a brief discussion of the role of food in the body, ie not just to provide energy but also the raw materials for building and repairing the body and dozens of other things. It touched briefly on the importance of water, which will be discussed more fully later in the book. My biology text also emphasised the role of water in just about every process in the human body. It has vital differences to every other liquid and is essential on the cellular level. It's not just there to flush out salt and keep blood flowing! Lots of the molecules in your cells (or was it all of them?) can't even attach to each other without water. We'd just fall apart.

The authors talked about what constitutes valid, reliable research and how we know whether we can trust new information, ie peer reviewed journal articles vs claims on a website trying to sell you a weight loss protein bar.

Finally they discuss how recommended dietary intakes are established, including how more of an essential vitamin does not mean better, and talk about how to do a nutrition assessment of an individual or a population.

The book includes access to a website with quizzes and stuff but, frustratingly, I haven't been able to log in yet. I'm really impressed by the book though, it is very clear and interesting so far. It seems to get across a lot of information without being overwhelming.


  1. Calories are such an interesting topic, because they're based on burning something to ash in a lab which doesn't translate quite right to a human body (hence why people react differently than others do while processing certain foods, etc.) I think in our lifetimes we'll see a new valuation of food, but I don't know what it'll be!

  2. Totally agree Kyra! I bet a tree trunk would give off a lot of energy when you burnt it to ash but that doesn't translate to what would happen if you ate it!

    Even with the recommended daily intake of various nutrients, there is huge variation from person to person so they have to look at averages of large populations. One day they will be able to personalise it much better.