Can we cut sugar levels in our food?

Products such as Mothers' Pride, which is owned by Hovis, have much lower salt levels than 50 years ago

The amount of sugar in some packaged food must be reduced, the health authorities say. It is an approach that has worked before, with salt - but can the trick be repeated?

Fifty years ago, everyday products, from bread to tinned vegetables, had much higher salt levels. Then, the government got involved and targets were set. A typical loaf of bread now has 40% less salt than it did in the 1980s, with about a 10% reduction in just the past three years.

The gradual changes went largely unnoticed by consumers and led to an adjustment in the nation's palate.

Now, Public Health England says a similar programme for sugar - in products such as biscuits, cakes, puddings, yoghurts, cereals and drinks - along with reductions in portion size, would have positive health benefits.

Watch Jim Reed's film in full here.

A 50% reduction in the amount of sugar from these foods would lower sugar intakes for adults from 12% to 9% of energy and for children and teenagers from about 15% to 10%.

Alternatives

Some food and drink companies have already reduced the sugar content of some products in large steps, maintaining sweetness by adding a no- or low-calorie sweetener.

In fact, one of the expanding areas of food manufacturing is alternatives to sugar - there are many natural and artificial alternatives on the market.

Fizzy drinks are some of the products using alternative sweeteners

One plant, Stevia, is 200 times as sweet with none of the calories. Unheard of four years ago, it is already used in dozens of big brands such as Heinz ketchup and baked beans, Coca Cola Life and Sprite. Often, it is introduced gradually, and buried away deep in the ingredients list.

Olivier Kutz, from Pure Circle, which produces Stevia products, says some brands or manufacturers will list it clearly on the label. "Others choose not to shout about it for various reasons - it could be because it's an everyday product and they don't want to confuse consumers," he says.

Some consumers are wary about artificial sweeteners - aspartame was removed from Diet Pepsi in the US earlier this year after concerns about potential side-effects.

Frighten customers

For big supermarkets, it is that same juggling act. They say they want to move people away from unhealthy foods but cannot afford to frighten customers off.

Nick Canning, joint managing director at Iceland, says it is a "huge danger" that customers will not like a new recipe, as they have to go through a gradual process to change their taste.

"If you take all the salt out of a ready meal for instance, then customers won't buy it. It will taste bland, it will taste manufactured. It's not what they want and not want we want," he says.

"We cannot just take a population which is ingrained in their eating habits and expect them to change them overnight."

And there is another problem with removing sugar from recipes - it causes technical problems.

Scientists bake cakes with different levels of sugar and alternative sweeteners

At Nottingham Trent University, food scientists experiment with baking cakes with different levels of sugar and artificial sweeteners - the results, in terms of taste and appearance, are mixed.

Senior food lecturer Christine Walker says: "Sugar has functions within the recipe, as most things do. Of course it provides sweetness and adds to the pleasant flavour, but it also adds texture to it and it also has a caramelising effect so it browns, so it's aesthetically pleasing. We eat with our eyes, so if it doesn't look good, we're not going to eat it.

"So it has those things and and if you start to take sugar away from it, those things may well be changed."

The government report suggests that for some confectionery, portion-size reduction may be an easier way of cutting down on sugar levels.

In the meantime, Ms Walker and her team will keep experimenting. "You can take it out. It's whether customers will buy it, because that's the bottom line isn't it? It's one of those things, trial and error. But the customer says they want less so we try very hard to do that," she says.

If obesity is - as the government says - the biggest public health threat facing our children, then we might have to accept the food we buy will have to change. And the companies selling us the stuff may have to work harder to come up with recipes that are not just good for our palette but our waistline too.

Watch Jim Reed's series of films on sugar and the obesity crisis here.

The Victoria Derbyshire programme is broadcast on weekdays between 09:15 and 11:00 on BBC Two and the BBC News channel.