Why has sugar become such a big issue?
The government is under unprecedented pressure as a result of Public Health England’s (PHE) report on Thursday, Sugar Reduction: the Evidence for Action. It called for a sugar tax of 10% to 20%, a crackdown on the marketing of unhealthy foods to children, and a rolling programme of reformulation of food products to reduce sugar in our diet. It portrayed sugar as a huge health problem and said the international evidence meant ministers should take robust, urgent steps to reduce sugar-related harm.

Medical groups and health charities have been calling for more effective action on obesity – and especially the imposition of a 20% sugar tax on soft drinks, sweet treat foods or both – for some years.

Jamie Oliver’s recent documentary, Jamie’s Sugar Rush, included graphic evidence of the scale of the problem. One doctor told how very young children sometimes need to have all their teeth removed because they are so rotten, and cited sugary drinks as a key reason.

How much sugar do we all eat?
Too much. For health reasons, none of us should get more than 5% of our total daily dietary energy from sugar. But PHE’s report revealed that both children and adults typically get between 12% and 15% of their energy from it.

Is this a particular concern among children?
Yes. PHE points out that: “Average daily ‘added’ sugar (non-milk extrinsic sugars) intake for 11- to 18-year-olds is 74.2g per day, and for 19- to 64-year-olds is 58.8g per day. These are 15.6% and 12.1% of food energy intake respectively, or 15.4% and 11.5% of total energy intake.”

Why 5%? Who came up with that figure?
In March, the World Health Organisation (WHO) revised down its estimate of how much of our energy should come from sugar from 10% to 5%.

It said: “A new WHO guideline recommends adults and children reduce their daily intake of free sugars to less than 10% of their total energy intake. A further reduction to below 5% or roughly 25g (six teaspoons) per day would provide additional health benefits.”

The main problem, the WHO explained, is: “Much of the sugars consumed today are ‘hidden’ in processed foods that are not usually seen as sweets. For example, one tablespoon of ketchup contains around 4g (about one teaspoon) of free sugars. A single can of sugar-sweetened soft drink contains up to 40g (about 10 teaspoons) of free sugars.”

Does the UK agree with that advice?
In July, the scientific advisory committee on nutrition (SACN), which advises the government, endorsed the ambition that no one from the age of two onwards should get more than 5% of their energy from sugar. It was the first time the panel had advised that consumers should minimise their intake of one specific food.

SACN also recommended that both adults and children should minimise their consumption of sugar-sweetened drinks.

PHE believes that if people did both those things “within 10 years we would not only improve an individual’s quality of life but could save the NHS, based on a conservative estimate, around £500m every year”. Obesity costs the NHS an estimated £5.1bn a year.

The government has accepted SACN’s recommendations.

What exactly are “free sugars”?
Mostly sugars that manufacturers have added to foodstuffs to sweeten them. They are different to the naturally occuring sugars found in fruit.

To quote the WHO: “Free sugars refer to monosaccharides (such as glucose, fructose) and disaccharides (such as sucrose or table sugar) added to foods and drinks by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates.”

Jennifer Rosborough, campaign manager and nutritionist from the campaign group Action on Sugar, says: “Sugars which are naturally present in milk and milk products and naturally occurring sugars in fruit and vegetables can be consumed as part of a balanced diet. The sugars in fruit and vegetables are still contained within the cellular structure of the food and contain many other nutritional benefits such as fibre, vitamins and minerals”. In contrast, free sugars are the unhealthy sugars in our diet, she adds.

Where does the sugar we consume come from?
It is the same for both children and adults, PHE found. “They include soft drinks; table sugar; confectionery; fruit juice; biscuits, buns, cakes, pastries and puddings; breakfast cereals; and alcohol drinks (for adults), with some foods making a larger contribution in different age groups,” its report said.

How much of a problem are sugary drinks?
Soft drinks, excluding fruit juice, are the largest source of sugar that children and young people aged 11 to 18 consume, and give them 29% of their daily sugar intake. Those who consume them drink on average a can a day. The biggest other sources are table sugar and confectionery (21% each), and fruit juice (10%).

How is sugar intake linked to ill-health?
Consuming too much sugar through your diet is closely associated with becoming overweight. That in turn increases the risk of some of Britain’s biggest killers: heart disease, type 2 diabetes, stroke and certain cancers.

Already 62% of adults in England are either overweight (37%) or obese (25%), according to the most recent data, which goes back to 2012.

In England, 13% of four- to five-year-olds are overweight and another 10% are obese; so almost a quarter are fat. The figures are even worse for pupils in their last year of primary school. Among 10 and 11-year-olds, 14% are overweight and 19% are obese; that’s one in three children of that age whose weight is unhealthy.

However, Dr Alison Boyd, the director of industry lobby group Sugar Nutrition UK, points to three other explanations for the recent rise in obesity: “The lower overall nutritional quality of diets, increased average caloric intake and decreased levels of physical activity have all been posited as significant influences. Singling out sugar may seem a simple, quick fix solution but risks ignoring many other factors that can contribute to lifestyle diseases.”

Sugar also causes tooth decay. A third of five-year-olds and almost half of eight-year-olds have some decay in their milk teeth, as do 34% of 12-year-olds and 46% of those aged 15.

Can too much sugar kill?
A study published in the medical journal Circulation in June found that sugary drinks contribute to an estimated 184,000 deaths a year worldwide: 133,000 from diabetes, 45,000 from heart disease and strokes, and 6,450 from cancer.

Such drinks are implicated in the loss of 1,316 lives a year in the UK alone, said the researchers, led by Dariush Mozaffarian of Tufts University in Boston in the US.

Is sugar consumption going up or down?
This is one of the most contested issues in the debate about sugar. The sugar industry says it is falling. Rosborough points to official national diet and nutrition surveys which show that sugar intake went down in some groups between 1992 and 2012 but increased in other age groups from 2008-10 and 2010-12.

Prof Graham MacGregor, the chairman of Action on Sugar, says: “The truth on this question is very hard to establish. We don’t really know if intake is rising or falling. Dietary surveys are totally unreliable as to how much sugar we all have.

“But we suspect that because so many products have got so much sweeter in recent years that sugar intake is going up. Most people want to reduce their sugar intake – they don’t add sugar to their food the way they did 50 years ago – but it’s hidden in so many products.”

What will happen next?
A team of Downing Street officials and ministers from across Whitehall are drawing up a childhood obesity strategy, which is expected in January.

David Cameron has ruled out a sugar tax. Sources involved say he is keen to produce a meaningful strategy that will be welcomed by the likes of Oliver and the medical profession, but that he is constrained by the knowledge that many in his party and the food industry will complain if it is too tough.