Obesity is a complex problem – there is no one cause and many factors contribute to the issue.

We know that it is a serious problem in the UK and it urgently needs to be addressed. In the UK, two-thirds of people are now classed as overweight or obese, while one in three men and almost one in two women are not active enough for good health.

In my role as General Manager of Coca-Cola Great Britain and Ireland, it is something I should and do think about and, like all food manufacturers and retailers, I believe there is a role we can play in helping government and others tackle this problem.

Coca-Cola is one of the best-loved and most iconic brands in the world and this brings opportunity. With that also comes responsibility and we aren’t shying away from that. You can read here about the progress we’ve made and the actions we’ve taken including reducing the average calories per litre in our sparkling drinks by 5.3% in the last three years.

But for me, there are two key parts of the obesity debate that aren’t being discussed widely enough – the importance of choice and the role of physical activity.

First, choice. Consumers should be in control of the choices they make and it is our responsibility to make sure they have enough options on the soft drinks aisle and the necessary information to make the right choices for them and their families.

Over the years, to meet changing consumer taste, diets and lifestyles, we have innovated to launch new drinks or reduce calories in existing ones and if you go into your local supermarket today, you’ll be able to choose from a wide range of low or no calorie drinks from Coca-Cola: because all of our major brands have a no-sugar/no-calorie, or low-calorie alternative.

Soft drinks is, in fact, the only food and drink category that provides such a wide range of choice and, importantly, the drinks taste good as well as containing no sugar or calories. As a food and drink industry we need to keep innovating to provide our consumers with low or lower calorie options. But this isn’t as easy as it sounds - reducing the sugar content of our drinks and retaining their great taste is challenging and costly. But we are investing in reformulation because we recognise it is beneficial for some consumers and we have seen a positive response from our customers and shoppers to the work we’ve done so far.

As well as offering choice, we also need to make sure that choice is better understood. Recent research with our British consumers showed that despite it being written on the can and referenced in our advertising, five out of 10 consumers do not realise Coca-Cola Zero is a no sugar, no calorie drink. This is one of the reasons we’re changing the way we market Coca-Cola by adopting a new ‘one brand’ strategy that will make more people aware and improve people’s understanding of the choice we offer.

Our new pack designs and advertising emphasise the distinctive benefits of each of our products, making choice easier and simpler for consumers. Each product will clearly highlight the different choices available using distinct colours and clear ingredient descriptors and information.

With this new approach we’re putting choice at the very heart of our business strategy and our aim is for Great Britain to be the first country in the world where more than half of the Coca-Cola we sell will be lower or no calorie.

So we believe we are playing an active role in helping people reduce their sugar and calorie intake. We will continue to do this. But a narrow focus on diet alone, or one type of food or drink, or even just one nutrient, like sugar, will not address the problem effectively. A more holistic approach is needed, with greater focus on the role physical activity can play in tackling obesity. As the scientific evidence of the many health benefits of being physically active mounts, public health professionals should cease to neglect the importance of getting people to be more active - as the recent Health Select Committee report highlighted. Alongside diet and nutrition, reducing our alarming levels of physical inactivity should be a key component of public health policy.

As the head of a drinks company, you may well expect me to say this. But the evidence suggests it is important. To give you a recent example, a long-term study from Cambridge University – which followed 334,000 people across Europe for 12 years – found that physical inactivity was likely to be responsible for at least as many deaths as obesity. In England, local authorities spend on average just four per cent of their budget on physical activity. I’m not arguing that diet isn’t important, which is why we’ve been reformulating our drinks, but four per cent is not enough.

And that’s why as a major brand we are working to inspire more people to be active – after all, communicating with consumers is one thing brands do well.

We have a long history of being involved in and promoting active lifestyles, from major sporting events to grassroots programmes. We are now investing £20 million to help get one million people active through our programmes by 2020 in Great Britain.

One of the ways we are doing this is through our ParkLives programme offering free family activities in the heart of local communities in Birmingham, Newcastle and the London borough of Newham.

What we’ve found interesting from the programme is that it’s not enough to put on free opportunities to get active and drive awareness of them, you’ve got to make them as compelling, as social, as fun as possible to get people to come and to then come back. So as we expand into three more cities in 2015, that’s where we’ll be bringing our marketing experience to bear, to get as many people as possible to be more active, more often.

We’re not the only ones involved in promoting choice or supporting physical activities. A number of brands and organisations are playing their part. This needs to be developed and encouraged so that together with a greater emphasis on providing and communicating choice, we can make real progress in addressing the challenge of obesity.