Sugar reduction is not a magic bullet in tackling obesity, a scientist has warned.
However, any product that brings excess energy to the diet is associated with weight issues and sugar may increase overall food intake because people like it so much, Professor Luc Tappy of the University of Lausanne said.
"For people with weight problems, sugar is one target to reduce, but it's not a magic bullet," he told an Ibec Nutrition and Health Foundation (NHF) conference in Dublin.
There was concern about sugar because consumption was at its highest level in human history at the same time as a surge in metabolic diseases.
However, claims that sugar was toxic or poison were unsupported by science and Professor Tappy said he would have concerns about extreme diets that sought to exclude sugar and carbs.
A lot more research was needed to establish its exact metabolic effects on the diet.
He said he felt taxes on sugar and sweetened beverages should only be introduced if there was clear evidence or likelihood they would have a significant impact, which currently wasn't there.
The World Health Organisation is proposing to lower the recommended limit for daily sugar intake to 5pc of total energy, but Professor Tappy said more research was needed to see if this would help reduce obesity, although the benefits of reducing sugar intake for dental health were proven.
A quarter of Irish children are overweight or obese as are 80pc of the over-50s, studies have shown. The conference also heard from food companies on what they are doing to make their food more healthy.
Derek O'Reilly, from Sodexho catering company, said consumers did start making healthier choices when they labelled the calories on canteen meals.
However, while people chose the healthier options such as fish or salad earlier in the week, by Thursday or Friday they tended to slip back to heavier options such as burgers, he said.
Ireland's women rugby players face a huge challenge eating well while rushing between early-morning gym sessions and full-time jobs, and their amateur status means they get far less recovery time between matches than professional male players, said international starPaula Fitzpatrick (pictured on left).
Huge planning and preparation was needed to eat the protein-rich diet needed for peak performance, she said.
The NHF is funded by the Irish food industry.