The easy way to calculate the HSR is to use the online calculator but for those of you who want to see the workings in order to better understand this rating system, here is the explanation. Be warned – this is long and complicated. There are several steps which must be completed in sequence in order to assess a food.

Where to find the relevant documents

All this material comes from the Health Star Rating website.To find these docs, go to the left-hand Menu and scroll down to Related Links – look for 3 pdfs/docs called Health Star Rating Style Guide, Instructions for using the Health Star Rating Calculator and the Guide to the Health Star Rating Calculator. Plus you can download an Excel file which is the Health Star Rating Calculator.

I made use of the ‘calculator’ supplied (simply an Excel file with some columns that autopopulate using a formula) to download and score a list of popular foods. So here’s what I learned along the way:

Before you start

Before you start, you’ll need to know:

1. All the numbers from the food’s Nutrition Information Panel for kilojoules, protein, fat, saturated fat, carbs, sugars and sodium per 100 g or 100 mL.
2. The percentage of fruit, nuts, vegetables or legumes – information which may not be available on packaging. This will have to come from the recipe or formulation. This includes fruits, vegetables, nuts including coconut, and legumes, seeds, spices, herbs, fungi and algae. These can be fresh, dried, frozen, canned or pickled as well as pureed or peeled.

Step 1: Work out which category your food falls into

There are three major categories in the HSR system, with two sub-categories for Dairy (D) under each of them:

Category 1 Beverages other than dairy beverages

Category 1D Dairy beverages

Category 2 All foods other than those included in Category 1, 1D, 2D, 3 or 3D

Category 2D Dairy foods other than those included in Category 1D or 3D

Category 3 Oils and spreads (butter/margarine)

Category 3D Cheese and processed cheese (with calcium content >320 mg/100 g)

So the first question to ask is: Is the food a dairy food?

That is, is it milk, cheese or yoghurt or ‘alternative’ like soy yoghurt or rice milk AND does it have a calcium content >320 mg per 100 g OR 80 mg per 200 mL (10% of the RDI)? If so, then it classifies as a dairy food.

If it’s not dairy, then decide if your product fits in as a beverage -1D, OR anything else – 2, OR an oil/spread - 3.

In the calculator, you have these choices:

• Beverages, non-dairy
• Core Cereals
• Core Dairy - beverages
• Core Dairy - cheese
• Core Dairy - yoghurt, soft cheese
• Fats, oils
• Fruit
• Non-core foods
• Protein
• Vegetables

Step 2. Calculate your HSR Baseline Points

For Category 1 and 2 foods:

HSR baseline points are calculated for the average quantity of kilojoules, saturated fat, sugars (this means natural plus added, not just sugar or honey) and sodium in 100 g or 100 ml of the food. These figures come from the nutrition information panel. Generally capped at 30 baseline points.

Step 3. Calculate your modifying points

3A. HSR V Points may be scored for the amount of fruits, vegetables, nuts and legumes (FVNL) in a food to a maximum of 8 points. This includes fruits, vegetables, nuts including coconut, and legumes, seeds, spices, herbs, fungi and algae. Fresh, cooked, dried, frozen, canned, pickled are included as are pureed or peeled.

3B. HSR P points can be scored if your food scores less than 13 baseline points.

3C. HSR F points for fibre can be scored up to a maximum of 15 points for P and F.

Step 4. Calculate your final score

Start with your total baseline points then subtract your modifying points V, P or F using the formula:

Final HSR score = Baseline points – (V points) – (P points) – (F points).

The lower the score, the better! Which is why they’ve turned it around with the Stars.

Use the table in the Guide to assign a star rating to your food depending on which of the six Categories it falls into.

The maximum is five stars with half a star in between from 0 to 5.

This scoring system is going to be used to determine if a food can make a health claim on pack. Foods with 4 or less stars are NOT eligible to make a health claim e.g. "This food is rich in calcium which builds strong bones”.

Worked example

Hypothetical sweetened soft drink

This fizzy drink already carries a Nutrition Information Panel:

Step 1 -Which category does this drink fit into?

It’s a beverage but not from dairy so is in Category 1.

Step 2 - Calculate your HSR Baseline Points

Use the table to work out the points in Column 1.

Baseline Points for Category 1, 1D, 2 or 2D Foods

I work out that this drink has:

• 0 points for its energy,
• 0 points for its saturated fat,
• 2 points for its 11% sugar plus
• 0 points for its 15mg of sodium.

So: Baseline points = 0 + 0 + 2 + 0 = 2

Step 3 - Calculate your modifying points

V points - This soft drink doesn’t have any fruit, vegetables, nuts or legumes. So its V points are 0.

Protein (P) points - It has 0.2 g of protein so scores zero protein points.

Fibre (F) points - Beverages (Category 1 foods) cannot score F points.

HSR Protein (P) and Fibre (F) Points

Step 4 Calculate your final score

The Health Stars score = 2 – 0 – 0 – 0 = 2

Step 5 Assign your score a Star Rating depending on which of the categories it is classified into:

*All foods other than dairy not in Category 1 or 3

# All dairy foods not in Category 1D or 3D

The result

So for Category 1 (Non-dairy beverage), my score of 2 means the drink can carry ONE star. Pretty amazing as I thought it would get a zero! The reason why not is that we’re only calculating the Star Rating on 100 mL (less than half a glass) while in fact most people guzzle a 370 mL can - which is over three times as much.