A study of children in 15 countries found those in Scotland took part in the least exercise and spent the most time watching TV and playing computer games.
The “global matrix” of children’s physical activity, produced by academics from around the world, found that Scotland is lagging behind countries from New Zealand to Mozambique in terms of childhood activity.
It assessed nine categories, including active play and sedentary behaviour, awarding each a grade between A and F.
If we don’t change their pattern of behaviour now, we risk passing inactivity and obesity down through another generation
Scotland’s children came bottom in both the physical activity and “screen-based leisure time” categories, scoring an F in both.
This comes despite the study praising the availability of parks and playgrounds across the country and the work of the Scottish Government in investing in schemes to tackle obesity.
Scotland was awarded B grades for “built environment” and “government strategies”, leading to calls for parents to ensure their children shun the television for outdoor games.
Tory health spokesman Jackson Carlaw called on parents to take “personal responsibility” for their children’s health and do “everything they can” to take part in more physical activity.
He added: “If we don’t change their pattern of behaviour now, we risk passing inactivity and obesity down through another generation.”
John Reilly, Professor of Physical Activity and Public Health Science at Strathclyde University, who was involved in the research, said: “No single country has found a magic formula.
"Countries tend to score well in some categories, such as in the community and built environment, but badly in other areas, such as overall physical activity, and this suggests there is great untapped potential for nations to learn from each other, in order to improve the health of children.”
The report is published in the Journal of Physical Activity and Health.
The Scottish Government has provided more than £5million to local authorities to help them meet a target of providing at least two hours a week of physical education in primary school and two periods in S1 to S4 over the past two years.
Officials say that a recent Youth Sport Strategy will allow schools to become sports hubs, while competitive sports between schools will expand in a bid to capitalise on the Commonwealth Games.