Too much sugar may be bad but there is no compelling evidence that alternative sweeteners are better for weight control and health, according to a report by European researchers prepared for the WHO.

Their meta-analysis of 56 studies found that non-sugar sweeteners were associated with only small improvements in BMI and fasting blood glucose levels in adults.

Children using sweeteners had a smaller increase in BMI than peers consuming sugar, but there was no difference in body weight between the two groups, the University of Freiburg-led researchers wrote in the BMJ.

For overweight and obese participants trying to lose weight, there was no evidence to show sweeteners could help.