Many of us are well versed on the negative health consequences of being obese. For those of us who aren’t, public health marketing campaigns like Take Life On here in Scotland and Live Well in England endeavour to spread the word and highlight the benefits of eating healthy, exercising regularly and maintaining a healthy weight. The message at the heart of these campaigns is a critical one.
The negative health implications of being obese are wide-ranging. Adults with a Body Mass Index (BMI) over 30 are vulnerable to various conditions associated disease and death including cardiovascular disease, osteoarthritis and some cancers. There are, economic consequences too. The most recent estimate we have suggests that, here in Scotland, obesity and related illnesses cost the NHS over £175 million in 2007/2008, with the cost to economy as a whole over the same period in excess of £457 million.iv This, of course, is not just a Scottish problem. A report published last month suggested that obesity costs Britain as a whole £47 billion a year, generating an annual loss equivalent to 3% of GDP.
So just how big of a problem is obesity in Scotland? Each year, on the Scottish Health Survey, we weigh and measure around 5000 adults and nearly 2000 children, providing the most robust estimates there are of BMI in the Scottish population. The latest figures, published today, show that nearly 1 in 3 adults (27%) in Scotland are now obese and around two thirds (64%) are overweight or obese. And while 70% of children fell in the healthy weight range in 2013, one in six (16%) remain at risk of obesity. In addition, the inequalities persist, with adults living in the 20% most deprived areas of Scotland significantly more likely than those living elsewhere to be obese. Given the health implications and subsequent burden on the NHS this is hardly great news. Scotland has one of the worst obesity records among OECD countries iv and, along with the rest of the UK, ranks uncomfortably high in the global obesity league table.
One of the major advantages of the Scottish Health Survey is that it’s carried out regularly, allowing us to monitor health trends, including obesity, over time. Since the survey was first carried out back in 1995, we now have trend data spanning nearly two decades. In the earlier years of the time series, obesity prevalence among 16-64 year olds increased sharply from 17% to 26%. In the last 5 years, however, there has been no significant shift in the proportion of the population with a BMI of 30 or more. In 2008 25.7% of 16-64 year olds were obese and the latest estimate is that 25.6% were in 2013. We’re seeing a similar pattern with children.
The full set of findings from our sister survey, the Health Survey for England, are being published on 10th December, but early findings released last month suggest that childhood obesity in England may also now be stabilising. While a recent report from the OECD suggests that Canada, Italy, Korea, Spain and the United States are all experiencing similar trends.
Good news surely? It’s certainly encouraging, but a note of caution, while the rise in obesity looks like it may have come to a halt, the same can’t be said for waistlines which are showing no sign of stabilising just yet. Between 1995 and 2012/2013, the average waist circumference for men aged 16-64 increased by 6 centimeters (from 90.2cm to 96.2cm in 2012/2013). Over the same period there has been an even larger increase in women’s mean waist circumference, increasing by 8.7cm (from 78.5cm to 88.7cm).
A raised waist circumference is defined as more than 102 cm for men and more than 88 cm for women. The proportion of men aged 16-64 with a raised waist circumference increased by nearly 15 percentage points between 1995 (14.3%) and 2012/2013 (28.9%). For women, prevalence has continued to rise, albeit at a slower pace than in earlier years (19.1% in 1995 and 47.0% in 2012/2013).
This trend matters because abdominal obesity - the accumulation of fat around the middle, puts a person at increased risk of heart disease and type 2 diabetes. It is also reported to be more highly correlated with metabolic risk factors (high levels of triglycerides, low HDL-cholesterol) than elevated BMI. So it’s important that, where possible, BMI is analysed in combination with waist circumference when monitoring individual and population level obesity.
With over a quarter of adults still obese and a third of men and half of women with raised waist measurements, its clear that tackling obesity is going to remain a key priority for government and public health professionals for some time to come.
The Scottish Health Survey in full is available here. Blog originally published on The Conversation UK.