MORE than a fifth of people in Scotland do not manage a twenty minute walk once a year.

Dr Catherine Calderwood, the country's new Chief Medical Officer, released the shocking statistic in Glasgow as she spoke of her determination to reduce health inequalities and tackle major concerns including rising obesity rates.

She said supermarkets had developed "very sophisticated" methods of persuading people to buy certain foods and for many people, unhealthy choices came down to "availability and price."

Dr Calderwood was speaking at a conference looking at government policy on health, organised by Glasgow University.

She showed a picture of the actor Brad Pitt and his wife, Angelina Jolie, heavily pregnant and both glowing with health and another picture of an overweight woman with a cigarette.

She said: "Do we tolerate that this is what we see around us?

"When you step off the train at Central, and that's what people look like, is that really acceptable?

"32% of pregnant women smoke in deprived areas and 5% of pregnant women smoke in posher areas.

"The same pattern is seen for physical activity.

"Sporty people have got sportier and 21% of the population does not walk for 20 minutes once a year.

"So the message has got out but it hasn't got out to everyone.

"And I think it's probably a problem with our messaging."

Dr Calderwood said a drop in obesity rates amongst primary one children had only occurred because of the higher rate of decline in children from affluent areas.

She said: "The rate is falling, however the wealthier children are responsible for the fall.

"Poorer children are getting fatter.

"I want to see that in poor areas and I don't want it to take 15 years.

"I don't know what the answer is necessarily but we've got to do something.

"The message is not getting through to deprived communities. I'm not prepared to blame the people who are perhaps not receiving the message.

"When the message was put out that it was safer to put a baby to sleep on its back, the rate of cot death dropped within weeks in affluent areas.

"It took 15 years longer for the rate to drop in deprived communities.

"I'm sorry but I'm not prepared to blame the babies for that."

She also spoke of her aim to reduce "unnecessary" variation in treatment across Scottish health boards.

She said: "In one health board the induction rate for pregnant women is 18%, in another health board it's 32%.

"I have no idea what the proper induction rate is but it cannot be both.

"I'm afraid I'm not prepared to blame the wombs or the women.

"In orthopaedics one unit has double the length of hospital stay as another for knee replacement. Again, I'm not prepared to blame the knees."

When asked if social media could be used to help get key health messages across she suggested it could, citing research which showed that that 100% of Scots under 35 have a smart phone, in both the most affluent and most deprived areas.