Obesity reduction will be challenging, scientists warn

14-Sep-2016 - Last updated on 15-Sep-2016 at 09:19 GMT

Childhood obesity can only be solved by reducing overall calorie intake

Food experts and lobby groups have criticised the government’s long-awaited childhood obesity strategy for focusing too heavily on sugar at the detriment of overall calorie intake.

In the strategy, published last month, the government set out a challenge to the food industry to reduce sugar by at least 20% “across a range of products” by 2020, including a 5% reduction in year one.

It re-emphasised its commitment to a levy on sugary soft drinks by 2018, and there was a focus on increasing childhood exercise and school sports.

While supporting the exercise proposals, Tom Sanders, professor emeritus of nutrition and dietetics at King’s College London and governor of the British Nutrition Foundation (BNF), said the strategy failed to focus on how to restrict overconsumption of food energy.

“Both fat and carbohydrate consumption need to be cut,” said Sanders.

“As most food energy comes from carbohydrate, the focus should be on reducing portion sizes of carbohydrate-rich foods, being careful not to replace it with fat.

Swapping added sugar for starches

Sanders believed swapping added sugar for starches wouldn’t help because they provide the same number of calories per gram.

“Cutting sugar from drinks and confectionery will help reduce the intake of calories but probably more empty calories come from crisps and other deep fried foods, which are high in fat,” he added.

The BNF also claimed that portion sizes, alongside reformulation, would be key to achieving the overall target for some product categories.

Sarah Coe, nutrition scientist at the BNF, said the universal 20% sugar reduction target would be difficult to achieve for some categories, such as low water content foods like cereals and confectionery, particularly if a simultaneous calorie reduction was also required.

“Healthy eating is about more than just sugars intake,” said Coe. “A healthy, balanced diet, as depicted by the new Eatwell Guide, should be the focus of healthy eating advice in the UK.

‘Targeted for reduction’

“The new dietary reference value of 5% of energy refers to free sugars specifically, not total sugars – so not all forms of sugars are targeted for reduction.

“In efforts to encourage free sugars (and calorie) reduction, the contribution to essential nutrient intake of foods that provide other forms of sugars (in particular fruits and milk-based products) needs to be considered carefully.”

Tom Chess, a biochemist at Cambridge University and chief scientist at Sugarwise UK, said that while having measures in place to encourage reduction of added sugars in food and drink should be commended, “it is technically very challenging to differentiate between the amount of sugar that has been added to food and the amount that is naturally occurring”.

He suggested that manufacturers should not be relied upon to certify their own claims.

“As far as I am aware, the Sugarwise test is the only means of independently assessing manufacturer claims on added sugar in the world.”