Swapping sugar for starch may combat obesity

A new study suggests that replacing sugar in the diets of obese children with starchy foods like crisps and pizza dramatically improves their health. It follows calls by health professionals, academics, nutritionists and campaigners for a tax on sugar to protect the health of children.

According to Professor Robert Lustig, an American paediatric endocrinologist, who carried out the research, replacing sugar, including fructose, with starchy foods in the diets of 43 obese children reversed their metabolic syndrome – a combination of diabetes, high blood pressure and obesity – within ten days. This is despite the children, who were aged nine to 18, consuming the same number of calories in starch as they had in sugar.

The children who took part in the study were given nine days of food with the same fat, protein and carbohydrate content as what they ate at home, and told to weigh themselves daily. The added sugar in their diet was reduced from 28 per cent to 10 per cent and the fructose – believed to be more harmful to health – from 12 per cent to 4 per cent of their total calories. Sugary food was replaced with starchy foods such as turkey, hot dogs, crisps and pizza.

The children’s weight reduced, as did their blood pressure and cholesterol levels. Their glucose tolerance, insulin levels and liver function test results improved.

Professor Lustig from the UCSF Benioff Children’s Hospital San Francisco, who was first to highlight the dangerous effect fructose can have on people’s health if consumed in large amounts, says the findings of the study suggest that the ‘health detriments of sugar, and fructose specifically, are independent of its caloric value or effects on weight’.

But academics and health charities have questioned the reliability of the results.

Tom Sanders, professor emeritus of nutrition and dietetics at King’s College London, said, ‘This paper’s claim of turning sugar into fat needs to be viewed with some caution because this is an uncontrolled trial. As the study lacked a control group who remained on a high-sugar diet, the claim that sugar is more fattening than starch was actually not tested for.

‘Instead, the comparisons were made with reports of “usual intake”. But it is well known that obese children underestimate and under-report food intake, particularly of soft drinks and snack foods.’

Diabetes UK said that the results should be ‘treated with caution’. Its clinical advisor Douglas Twenefour said, ‘These results come from a small study that did not compare children eating a low-sugar diet with children who continued to eat a high-sugar diet. It also did not follow the children’s longer-term health, and the work does not provide enough evidence to show that sugar intake alone (rather than overall calorie intake) was responsible for the improvements seen. Diets that are high in sugar are contributing to the rise in obesity, and in turn to the dramatic rise in cases of type 2 diabetes, but a range of measures are needed to address this.’

The study was published in the journal Obesity the same week that a coalition of health professionals, academics, nutritionists and campaigners urged the Prime Minister David Cameron to follow in the footsteps of other countries and introduce a sugar tax to improve children’s health.