Arecent headline claiming that Scotland now has the fattest children in the world was an exaggeration, but not much of one.
A third of Scottish 12-year-olds are officially overweight, twice the figure for the UK as a whole and greater even than the trend of transatlantic teenagers.
Fast food and slow motion are the causes, illness and premature death are the grim results if those extra kilograms persist into adulthood, as they often do. Unhealthy eating and a sedentary lifestyle are habits that are hard to break.
This places a weighty responsibility on the shoulders of teachers, who now have to make sure that little heads are filled with understanding, tummies with fruit and vegetables, and leisure hours with running, jumping and active fun. But that is what A Curriculum for Excellence is all about.
"PE sits so comfortably with the development of the four capacities, which aim to produce successful learners, confident individuals, responsible citizens and effective contributors. I'm tempted to say you could do it all through the subject," says Liz McGhie, a PE teacher with Glasgow University. "It is very much about the whole child.
"There aren't going to be as many alterations to the PE curriculum as to some other subjects. It will come under health and well-being, though, instead of the expressive arts, which is an improvement. That will make it clear that PE is about children's social, emotional and mental as well as physical health."
Gaps in the curriculum may be few, but gaps in provision are plentiful and have been exercising minds from school halls to Holyrood. The announced aim of the Scottish Executive to have 400 extra PE teachers trained by 2008 looked wide of the mark when PE teacher numbers in primary schools fell by almost a fifth the following year (2004-05).
So, an idea that occurred to the Scottish Executive and Glasgow City Council at roughly the same time was to develop specialisms in addition to specialists.
"We now have 25 primary teachers completing a two-year postgraduate certificate course in PE," says Christine Watson, Glasgow's primary schools PE manager. "It's the first course of its kind in the country."
Funded by the education authority and developed with Glasgow University, the course combines theory and practice and aims to create teachers competent and confident enough to teach PE to primary pupils of all ages.
"They have to teach PE; it's in their contract," says Ms Watson. "But they are not experts and a lot of them aren't happy about it."
On the face of it, PE is a subject that demands aptitude as well as application. Getting the average primary teacher confidently doing forward rolls sounds like a tall order for a three-hours-a-week twilight course.
"We're not trying to do that," says Theresa Campbell, the senior PE teacher at Glasgow University and course leader. "Primary teachers can't be experts in every subject. They are, however, experts in how children learn.
"You don't have to be a skilled performer to teach PE. Teachers who aren't might even be better, because they understand how kids feel who can't do it right away. What you need are people who can motivate and include everybody - and that's where primary teachers excel."
It is perfectly possible to teach PE well without the teacher demonstrating every activity herself, particularly in gymnastics, says Marjory Tweedie, one of the council's primary PE specialists responsible for delivering the practical element of the new course.
"You talk the class through the activity with a child in front of you.
"When I'm teaching, I won't always demonstrate, and we didn't expect students on this course to do everything we showed them, though they could if they wanted to."
Talking regularly with like-minded people deepened the experience for Sheila MacKenzie of Bankhead Primary.
"We have done a lot of thinking and a lot of writing, which wasn't always easy. But it channels your thoughts, gives you the vocabulary, makes it so much easier to communicate," she says.
The highlight for Jim Boyd of Scotstoun Primary was the skills-based programme, which teaches the elements of physical activities such as running, jumping and ball sports to young children.
"For so long we've had this block-based system in schools: two blocks of gymnastics, say, then two of games, one of dance. So you teach racquet skills in P4 but not again until P6. If you did that with subtraction the kids would never learn," he says.
"When kids get to the age of 7 they develop self-perception and if that's poor because they haven't got these basic skills, they will look for excuses not to do physical activities, probably for the rest of their lives."
Learning has not been confined to the students on the new course.
Developing the course, marrying the academic with the practical and finding the best way to give primary teachers the skills, knowledge and understanding to teach PE with confidence, has been fascinating, says Ms Watson.
"There is a lot in the course and the students have got a lot out of it.
"We are now getting applications for next session, and Glasgow University and Edinburgh University will be rolling it out around the country.
"I will always remember this first cohort, though. It has been a unique experience."