Snack bars are convenient to put in kids’ lunchboxes or to keep on hand when you need a quick snack. But do they stack up to their healthy image? When we calculated the new “health star” ratings for 35 snack bars, we found only 9 that earned 3 stars or more.

Earlier this year the government gave the go-ahead to the health star system for rating food. This voluntary front-of-pack (FOP) label is a similar concept to the energy-efficiency star ratings you find on appliances and it’s designed to give you “at-a-glance” information about the nutritional value of packaged food. The ratings range from half a star to 5 stars – the more stars the better.

The health star system is based on nutrient-profiling criteria developed by Food Standards Australia New Zealand. It takes into account the “positive” as well as the “negative” aspects of a food.

The negative aspects are the nutrients associated with increased risk of chronic diseases: the food’s energy content, saturated fat, total sugars and sodium. The positive aspects are the food’s dietary fibre and protein – and also how much fruit, vegetables, nuts or legumes (including seeds and coconut) it has.

The star rating is based on 100g or 100ml of the product. Different nutrient thresholds are used for beverages, dairy foods, oils and spreads, and cheese products.

What we found

Many snack bars are high-energy snacks and shouldn’t be considered everyday eating (see “Energy hit”).

Their high energy, saturated fat and sugar meant most of the bars in our survey rated less than 3 stars.

Become a Gold or Silver member to find out more about how the bars rated.

Rating the ratings

We asked Cliona Ni Mhurchu, Professor of Population Nutrition at the University of Auckland and a member of the New Zealand Front of Pack Labelling Advisory Group, to comment on our ratings. She thought there was a good spread of stars across the category, so it should be easy for consumers to identify healthier choices.

“The positive aspects of a food can offset its negative aspects. So the food is being rated on its overall nutritional value,” Professor Ni Mhurchu said.

This can explain why the Quaker Nut Bar has a high rating: “Total fat, unlike saturated fat, isn’t strongly associated with the risk of chronic disease so it’s not considered when calculating the health star rating. Similarly, a high-sugar product may achieve a high rating if the majority of the sugar comes from fruit and it’s high in protein and fibre.”

We agree that having health stars prominently displayed on a food’s packaging will make it easier for consumers to identify healthier choices. But we have several concerns about how it will work.

Will it be used widely enough?

The health star system is voluntary. Manufacturers can choose whether to use the health star system on all their products, on selected products (those with a “better” rating), or not to use it at all.

The two main supermarket chains here have announced they’ll adopt the ratings for their home-brand products. Sanitarium, Nestle and Griffins have also announced they’ll use the health star system. But there’ve been no such announcements from other Kiwi food manufacturers – so it’s possible you won’t be able to compare all the options on a shop’s shelves.

The Australian government has said that if there isn’t widespread uptake of the health star system in five years, it’ll consider making the system mandatory. Our government hasn’t indicated whether it intends to do the same.

Are the stars effective?

Some consumer behaviour experts were surprised when the health star system was given the go ahead without any robust comparative research. Dr Ninya Maubach, from the Department of Marketing at the University of Otago, says this is totally inadequate. She is particularly concerned that no study here or in Australia has tested the final labelling format announced in June.

Dr Maubach recently published a study that compared different ways of identifying nutritional profiles, including a type of health stars label and “traffic lights”. The findings showed most people could recognise healthy products through either the stars or the traffic lights. But the traffic lights were much more likely to help people recognise less healthy choices.

The National Institute for Health Innovation at the University of Auckland is recruiting people to take part in its Starlight study. Starlight will use a smartphone app to find out what effect different types of FOP labelling, including the health star rating, have on food choices.

Will the system be monitored?

To be useful to consumers, any food rating system must be monitored and evaluated. Professor Ni Mhurchu said monitoring should look at whether the system was being taken up for enough products, whether the foods using the star system became healthier over time, and what effect the system had on consumer choice.

The Ministry for Primary Industries said this was on the cards. Although details of the monitoring and evaluation programme were still being developed, it would include an evaluation of consumer recognition, use and understanding of the system as well as how widely adopted by food manufacturers.

The nearest comparison to the health stars is the “guiding stars” shelf label used in supermarkets in the US and Canada. Products get points from positive nutrients and lose them for negative ones, and are rated from 0 to 3 stars. Research recently published in Public Health Nutrition found that sales of less nutritious foods declined after the shelf labels’ introduction; but there was no significant difference in the sale of more nutritious foods.

Will products be easy to compare?

The system isn’t only about health star ratings. Product labels can show other information – and manufacturers are being encouraged to show all of this:

  • a health star rating
  • an energy icon
  • three nutrient icons (one for saturated fat; one for sugars, one for sodium)
  • a fourth nutrient icon (this is a “positive” nutrient chosen by the manufacturer).

However, manufacturers can “pick and mix” what they show.

For example, on small packs (such as some confectionery) manufacturers can use just the energy icon – they don’t have to display the health star rating.

Manufacturers can also vary how a nutrient icon displays its information. On most foods it is to be shown per 100g or 100ml, but if the product’s intended to be consumed as one serving or is sold as a multi-pack it may be shown per pack. A “low” and “high” claim may also be made if the product meets the criteria for nutrient-content claims set out in the Food Standards Code.

We say

  • The health star system must provide useful information to consumers. We’ll be closely monitoring the programme’s implementation.
  • If manufacturers don’t take up the health star system, the government should make it mandatory.

Products compared

Become a Gold or Silver member to view the product comparison tables.