Who, What, Why: Can you reduce sugar in food without anyone noticing?

Tesco has announced it will reduce the level of sugar in its own-label soft drinks by 5% per year. But how can you reformulate recipes subtly, asks Chris Stokel-Walker.

The West has a sweet tooth. "Research by Public Health England shows children get around 14% of their energy from sugar," explains Paula Moynihan, professor of nutrition and oral health at Newcastle University. That's three times the level the World Health Organisation says it should be.

As a result, manufacturers are now reducing the levels of sugar in their foods. Tesco announced today it will cut sugar levels in its soft drinks by 5% each year.

This can be done in two main ways, explains Dr Philip Ashurst, an expert researcher in soft drinks. Plain sugar can be replaced, either by artificial sweeteners such as aspartame, or stevia, a plant-based product. Or, manufacturers can slowly reduce the sugar content step-by-step, allowing the public to realign their palates to reduced-sugar products.

This can be done without many people noticing in gradations of 5% or 10%, Ashurst says.

"The trick is to reduce the sweetness and acidity in proportion with each other," he adds. Simply cutting the sugar in a product while not recalibrating any of the other flavours in a drink, will make a change stand out. Toning down the sweetness by 5% can require a commensurate drop in acidity of the same level.

Manufacturers test products before making major changes publicly. Reformulating a product's recipe is a major change, and not one to be made lightly. Kellogg's has previously cut salt levels in its breakfast cereals drastically, and members of the public noticed.

General Mills, a large US food manufacturer, spent several years reducing the amount of sugar in its cereals. It had to increase levels of fibre because the product disintegrated in milk quicker without the high sugar levels. But the company found that children stopped liking the product if the sugar level fell below the level of 9g per 30g serving.

Tesco may face a similar problem to General Mills. Beyond a certain threshold, cutting out the sugar becomes noticeable in different ways to taste alone. "There will come a point when people say it doesn't taste like it used to; it's much thinner," Ashurst says. At that point, shoppers will vote with their wallet, and pick up an alternative.

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