England's chief medical officer yesterday mooted the idea as one way of dealing with the problem.
Dame Sally Davies told the Commons Health Select Committee she believed research would show sugar is addictive and a tax may be needed.
It was unclear whether she felt the levy should be introduced in England or throughout the UK.
Dame Sally said: "We have a generation of children who, because they are overweight and due to their lack of activity, may well not live as long as my generation.
"They will be the first generation that live less, and that is of great concern. We have normalised being overweight."
About 25% of all adults in Scotland are obese, with 64% of people aged 16 or over classed as overweight or obese, according to latest figures.
The food industry said it is currently working on reducing sugar in products.