TODAY I want to discuss obesity - a subject which isn’t always easy to talk about, despite being one of the biggest public health challenges Scotland faces.

The Scottish Government has just published radical new proposals aimed at tackling obesity and improving physical activity – and it’s no exaggeration to say this is one of the most important documents we will publish in this parliament.

According to recent Scottish Health Survey figures, two thirds of us are overweight or obese, with one in five kids at risk of developing those conditions.

A poor diet and unhealthy weight increases the risk of developing type 2 diabetes. It is also a risk factor for 13 types of cancer, cardiovascular diseases and depression.

Behind the statistics are real people, whose health and wellbeing – and potentially their life expectancy – are affected by their weight.

And treating these conditions is set to put ever more pressure on our health service. I have a lot of sympathy for people struggling to make the best choices around their diet. As I’m writing this, I’m acutely aware of my own lifestyle and how difficult it is to fit being healthy and active into our daily routines.

I’ve recently taken up running – trying to fit in a few kilometres here and there – and am consciously trying to take the stairs more instead of the lift.

Even after a few modest changes, I definitely feel the benefit – for instance I’m notably less breathless when I get to the top of the stairs.

I also try hard to take the healthy option at meal times, but when you’re surrounded by junk food all the time, it can be hard to resist the array of less-than-healthy options in front of you.

Although we’ve had some success in slowing the increase in weight gains in recent years, what we need is a step-change – and that is what our new strategy aims to deliver.

Clearly governments cannot – and should not – be trying to micro-manage people’s lives for them. But what we can do is make it easier for people to make positive health choices in their daily routines.

Over the last few years, the Scottish Parliament has shown itself capable of bringing forward bold public health measures.

It’s fair to say that the smoking ban wasn’t universally popular when it was introduced in 2006, but it has helped see cases of heart disease and strokes plummet, and the number of smokers fall to the lowest ever level. Our plans to introduce a minimum price for a unit on alcohol – ending the sale of cheap high-strength booze which causes so much social harm – have attracted international praise. Just last week the Labour-run Welsh Government announced its intention to introduce a similar policy.

Most obviously, we need to reduce the amount of unhealthy food we are eating. Despite living in a country which produces some of the finest food and drink in the world, our own diets can often leave a lot to be desired.

Around a fifth of the calories and fat we consume, and around half of the sugar, come from so-called ‘discretionary foods’ – treats and snacks – which are far more likely to be bought as a result of marketing promotions.

We’re therefore proposing tough new measures restricting the promotion of unhealthy food and drink that is high in fat, salt and sugar in certain areas like visitor attractions and schools.

Children are especially susceptible to TV advertising, and frustratingly this is one area where the key powers are reserved to Westminster.

We think it’s essential that TV adverts promoting unhealthy foods are banned before the 9pm watershed. We have called on the Westminster government to act – if they won’t, then we’ll demand the devolution of powers so we can take action ourselves.

We also need to encourage people to take small steps to increase physical activity, which can have significant long-term benefits. You’ve probably heard of the fantastic Daily Mile initiative – the brainchild of headteacher Elaine Wyllie, who got all of the kids in her school to walk, run or jog a mile a day. We’re working to roll this out in all schools and nurseries, and also working with the private sector to encourage take up in workplaces.

We must also support people who are particularly vulnerable to the health consequences of being overweight or obese. We are going to invest £42m over the next five years in a scheme offering weight management interventions as a core part of the treatment people with Type 2 diabetes receive - a group that can particularly benefit from losing weight.

I am delighted that our strategy has been so well-received. Jamie Oliver, who has long campaigned for healthier eating, has said that Scotland has set an example to the rest of the world, and has encouraged the UK Government to follow our lead.

But there is a long way to go. None of these measures on their own will solve our national weight problem overnight – but they will put us on the right track to a healthier future.