Reading Nutrition Labels


I decided to make my first content post about something many may take for granted – how to read nutrition information labels. This piece will focus on New Zealand labeling. Training related posts will come – however, this is an area I have noticed many ask about and/or have little knowledge of. If we can better understand how to read and interpret these labels then we can make better dietary choices, and thus increase our chances of achieving training and health goals.

Why should you listen to me? Fair question, I am not a dietitian. However, I have taught nutrition papers for several years and at university I did learn a thing or two in my biochemistry courses. Nutrition is an area I think everyone should have some knowledge of. Right, let’s get to it.

Reading Labels

Below is a picture of a nutrition information panel from a product. You’ll notice it has two quantity columns, the “Average Quantity per Serving“, and the “Average Quantity per 100 g“. The serving size is set by the manufacturer, while the per 100 g tells us useful information, as this directly converts to percentages – allowing us to directly compare similar products.

If we take a look at the rows we see several terms – “Energy“, “Protein“, “Fat, total“, “- saturated“, “Carbohydrate“, “- sugars“, and “Sodium“. The amounts of these products must be indicated, it is a requirement. Sometimes you’ll also see fibre, or certain micronutrients etc. listed – generally only if a product makes a claim regarding these, such as calcium which is listed on the above label.

What do these required names mean?

  • Energy – this is the amount of kilojoules or kilocalories (commonly referred to simply as calories) in a product. These are just two different names for energy, 1 kilocalorie (kcal, or often just ‘Cal’ as in the label above) is approximately equal to 4.2 kilojoules (kJ). Energy can be considered the fuel that food contains.
  • Fat – is a macronutrient that has a large contribution to fuelling the body, especially at rest and during low intensity exercise. It also plays numerous other important roles (e.g. insulation, absorption of certain micronutrients, cell membranes etc.). Fats aren’t just one compound – they include many types such as triacylglycerides (which contain fatty acids), cholesterol and more. Fats don’t mix with water (they are hydrophobic), which makes fat digestion, absorption and transportation an interesting area.
  • -saturated – indicates the amount of saturated fatty acids a product contains. The dash prior to this word on a label indicates that it is a part of fat – e.g in the label above total fat per serving is 3.0 g, of which 1.9 g is saturated fatty acids. It is the only type of fatty acid that must be labelled, others will only be included if claims have been made by the product. You may have heard saturated fatty acids referred to as ‘bad fat’ – while polyunsaturated (and monounsaturated) fatty acids may have been referred to as ‘good fats’. However, these ‘good’ and ‘bad’ references are currently debated.
  • Protein – is a macronutrient used primarily for structural purposes in the body, i.e. we use it for growth and repair, although it is involved in many other functions (e.g. hormones and enzymes) in the body. It can also used as a fuel, but is not usually a preferred fuel source.
  • Carbohydrate – another macronutrient predominately utilised as fuel. The carbohydrate on a label is the combined amount of both complex carbohydrate and simple carbohydrate a product contains. Carbohydrate is a major fuel source for the body – especially for high intensity activities.
  • – sugars – these are simple carbohydrates. Generally easy to digest and absorb, and hence get into the blood stream quickly. Again, the dash prior to this word on a label indicates that it is a part of carbohydrate – e.g in the label above total carbohydrate per serving is 13.0g, of which 12.2g is from sugars.
  • Sodium – is a micronutrient, specifically a mineral. It is an electrolyte and is involved in fluid balance. It has to be included on labeling because over consumption has been linked to cardiovascular disease.

Macronutrients & Energy

You’ll notice I used the word ‘macronutrient’ in my descriptions above. Macro means large, and nutrient means something that provides nourishment, so the term macronutrient therefore refers to something that is required in large amounts to nourish us.

Fat, protein and carbohydrate are three of the macronutrients our bodies require, the fourth – not required – is alcohol. Each of these macronutrients supply the body with energy. Fat with the most (9 kcal per gram), alcohol is next (7 kcal per gram), and protein and carbohydrates the least (each providing 4 kcal per gram). Hence, fat is considered the most energy dense macronutrient.

Energy density refers to the amount of energy per gram. If there is more energy per gram in a certain food when compared to another then it can be considered a more energy dense food. If we take in too much energy vs what we utilise then we gain weight, while if we take in too little energy compared to what we utilise then we lose weight (see here for an article about weight loss). Thus, someone wanting to gain weight might look to include foods that are more energy dense in their diet, while someone wishing to lose weight should choose foods with lower energy density.

When we view a label, a more energy dense food would have greater energy content per 100g. You could easily utilise this information at the supermarket by comparing two products of the same type (e.g. dessert options) and, if your goal is to consume less calories – or lose weight – select the product with the lower energy density.


The images above show you nutrition information from two desserts: a six pack of chocolate coated ice creams (each serve 49g), and an eight pack of fruit flavoured ice blocks (each serve 77g) – notice the per 100g and per serving columns for each of these products are reversed. Per 100g the ice cream contains more than 4x the energy of the ice block. While per serving the ice cream contains more than 2.5x the energy of the ice block- even though the ice creams serving size is far smaller!

Be aware that consuming a greater amount of an item with a lower energy density will still result in more calories being consumed – total calories taken in is the most import factor (in terms of nutrition) for weight gain or loss. So attention should always be paid to total calories consumed – you can overeat on almost any type of food (if you try hard enough).

The Small Details

The below images show us some things to watch out for when looking at similar products. Firstly, take a look at the serving size for each can of baked beans below. What do you notice? Well, one of the products has a serving size of 210g while the other has a serving size of 102g. What this means is that if you were to compare the energy content per serving you may be fooled into thinking the product with the red label contains less energy. However, the serving size of one product is much smaller, and the energy density almost identical (425kJ vs 435 kJ per 100g). So, if you ate the whole can (420g vs 410g), you would consume essentially the same amount of energy (1790kJ vs 1776kJ).


Secondly, take a look at the sugar content. Sugar has faced its fair share of attention recently and is something many people want to cut down on. When we compare these two products you can see that per 100g there is a difference of just over a teaspoon (~4g) with 7.4g vs 2.9g. So given the similar energy content, someone watching sugar intake may be best to choose the product with the red label.

Next, look at the sodium content. The difference is nearly 2x, with 450mg vs 255mg per 100g. Again, given the similarity in energy content and can size, the product with the red label comes up trumps with a lower sodium content.

One thing which these two factors may impact however, is flavour. Sugar and sodium can be used to enhance flavour, thus the product with less of these may not taste as good.

Finally, protein can be a very important factor – especially for those regularly involved in exercise (particularly resistance exercise). If weight training and hoping to add muscle mass, you may want to target approximately 1.6 g per kg of body weight – that would be 128 g per day if you weighed 80 kg. While around 1.0 g of protein per kg of body weight per day may be suitable for the general population. The images below show you nutrition labels from two yoghurts with vastly different protein contents.


When looking at the protein content we notice that per 100 g the yoghurt on the left has just under half the protein content of the yoghurt on the right (4.3 g vs 8.7 g). The energy density is remarkably similar (363 kJ vs 349 kJ per 100 g), while the sugar content is greater in the lower protein yoghurt (7.7 g vs 4.7 g per 100g). Safe to say which of these two yoghurts I would select if the prices were similar!

Final Thoughts

I have tried to keep this relatively brief, hopefully I have achieved that. The main things to take home when reading nutrition labels are:

  1. Pay attention to energy density (i.e. energy per 100 g) of similar products;
  2. Pay attention to recommended serving sizes – these can be vastly different between similar products; and,
  3. Pay attention to the small details – such as sugar and protein contents in similar products.

If the above three points are considered, you can make better choices to meet your training and/or health goals. In conjunction with making better choices when selecting foods, it can be helpful to track your daily eating habits. Personally, I recommend using an app, such as MyFitnessPal, to assist you in tracking your food intake throughout a day.

Thanks for reading! Feel free to share this with anyone who may find it useful.

If you have any questions feel free to ask in the comments section below.

Note: I will include a reference list when writing scientific posts. In today’s post you will see several hyperlinks which take you to relevant further reading if you wish to view these. I like hyperlinks, so will always take advantage of these (please let me know if these links have broken/died, so I can update!).

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