FactCheck: Is Ireland really one of the world's most obese countries?

A MAJOR STUDY published last week provoked headlines throughout the world, and especially in Ireland.

The paper, in the Lancet medical journal, tracked obesity levels in 200 countries, from 1975 to 2014.

It gave rise to claims that Irish people would be the most obese in Europe by 2025, but also that the British would occupy that position in 10 years’ time.

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One headline even claimed “Ireland’s obesity rate among world’s worst”, and Fine Gael Senator Catherine Noone used the Lancet study to support the introduction of a sugar tax, declaring in a statement:

Ireland’s chronic obesity problem needs to be top of our priority list in the formation of a Government.

Studies on obesity often cause widespread concern, sometimes rightly so. The medical risks associated with being severely overweight are very serious – diabetes, heart disease, and so on.

But with so many different claims being interpreted and repeated in different ways in different countries, what are the facts?

Ruth Talbot in Tipperary emailed factcheck@thejournal.ie to ask this very question. Here’s our answer.

Claim: Ireland will be the most obese country in the EU by 2025
Verdict: FALSE – We rank second according to the study in question, albeit only by a tiny margin.

The Facts

Let’s start with the basics.

Obesity is measured using “body mass index” (BMI). That’s your weight divided by your height squared.

Let’s say your weight is 76 kg (about 12 stone), and your height is 1.75 metres (about 5′ 9″).

There you go – your BMI is a reasonably healthy 24.8 kg/sq metre.

The World Health Organisation weight categories (which are the international standard), are:

• Underweight = less than 18.5 kg/sq metre
• Healthy = 18.5-25 kg/sq metre
• Overweight = 25-30 kg/sq metre
• Obese = more than 30 kg/sq metre
• Severely obese = 35-40 kg/sq metre
• Morbidly obese = More than 40 kg/sq metre

So how do we rank?

The Lancet

The major study published last Friday offers figures for men and women aged over 18. There are very significant differences between the genders, but to keep things simple, we’ll be using averages across both genders.

Here’s how we fare on mean body mass index (BMI)

As you can see, we have the highest average BMI in the EU – 27.4 kg/m sq, which is slightly overweight.

The countries with the highest and lowest BMI in the world are American Samoa (33.5 – considered obese) and Ethiopia and East Timor (both 20.55, slightly above underweight).

This is one way to measure overall bodyweight in a population, but it doesn’t tell us how much of a country’s population is obese.

This does:

We rank third in the EU by this measure. Some 25.55% of Irish adults are categorised as obese, behind Malta and the UK at 27.35% and 27.3% respectively.

Irish men also rank third in the EU, and Irish women rank fourth.

The highest rate of obesity in the world is 53.2%, in the tiny Cook Islands in the South Pacific, off New Zealand.

It should be noted that the Pacific Island nations, as a region, have the highest prevalence of obesity in the world, occupying the top 12 and 13 places for men and women, respectively.

The claim that Ireland’s obesity rates are “among the world’s worst” is way off. In actuality, we rank 27th in the world for men, and 76th for women.

The country with the lowest prevalence of obesity in the world is East Timor, at 1.95%.

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• At 8.2%, Ireland has the fourth-highest rate of severe obesity in the EU, behind the UK, Malta and Lithuania
• At 2.8%, we have the second-highest rate of morbid obesity in the EU, behind the UK
• At 0.9%, Ireland joins Spain and Lithuania with the lowest prevalence of underweight adults in the EU.

The Lancet study and its accompanying website don’t provide rankings for the category of “healthy” BMI.

But if we’re looking at extreme bodyweight, it’s probably worth seeing how many of us are within the “normal” range.

So we grabbed the raw data available on the NCD RisC website, and analysed it.

Here’s how we rank – including the highest and lowest in the world, top and bottom five in the EU, and selected others.

What the figures show is that Ireland has the fourth-lowest rate of healthy body mass out of 28 EU nations – at 38.09%, ahead of Greece, the UK and Malta.

Perhaps surprisingly, Rwanda tops the world ranking, with 70.4% of adults there having a BMI of between 18.5 and 25 kg/sq metre.

Less than 17% of adults in French Polynesia – a French territory in the South Pacific – are categorised as having a “healthy” BMI, the world’s lowest rate.

Now let’s see what The Lancet study has to say about the future.

A decade from now

In 2025, the researchers predict that the same four countries – Malta, Ireland, the UK and Lithuania – will be at the top of the EU rankings for obesity prevalence, albeit in a different order.

In 2025, Ireland will have the second-highest rate of adult obesity in the EU, at 37.65%, narrowly behind the UK (37.7%).

So the claim that we will be “the most obese” country in Europe by 2025 is technically FALSE, but you could very reasonably argue that, after rounding the numbers, our predicted prevalence will essentially be the same as the UK’s.

What is clear, according to the researchers’ projections, is that Irish men will have the highest rate of obesity in the EU within a decade – 38.4%. Irish women will be ranked second.

The data also show that:

• Irish adults are on track to have the fastest increase in the rate of obesity in the EU – up 12.1% from 25.55% in 2014 to 37.65% in 2025
• Irish adults had the EU’s fastest rise in obesity over the last few decades – from just 5.7% in 1975 to 25.55% in 2014, a 19.85% increase.

World Health Organisation

The WHO (the UN’s global public health agency) has comprehensive data for obesity and BMI, gathered in 2014. The results are not radically different, but there are some discrepancies.

• We rank fifth in the EU for obesity prevalence (as opposed to third)
• We rank 10th in the EU for overweight prevalence
• We rank 1st in the EU for average BMI

So for the sake of getting as close as possible to the facts, let’s map these two major global studies on to each other, by averaging out the figures for all 28 EU nations.

So our analysis of the Lancet and WHO figures shows Irish adults have the third-highest rate of obesity in the EU, as of 2014.

Health warnings

Body mass index wasn’t checked every year in all 200 countries since 1975.

The Lancet study relies on data gathered by authorities and academics in individual nations. Naturally, there are gaps, so the researchers also used a statistical model where other factors (income, education levels, access to food, and so on) are used to predict BMI.

So the final results depend heavily on estimations and projections, using fairly complicated statistical formulas and models. The numbers aren’t perfect.

This was a point made by former HSE regional manager, now journalist, Dr Jacky Jones last Friday, speaking to Matt Cooper on Today FM’s The Last Word.

When you read the actual methodology of the paper, it’s quite clear that some of the figures are estimated, based on previous figures.

She also claimed that obesity prevalence had actually gone down in Ireland in recent years, citing the SLAN report of 2007 and last year’s Healthy Ireland survey.

The 2007 study found a 25% rate of obesity, while the 2015 survey saw obesity at 23.5% – a 1.5% drop.

However, there is a cautionary note about that cautionary note.

While the 2007 report related to individuals aged 18 and over, the 2015 study also included 15-17 year-olds. This age group had an obesity rate of far lower than the overall average, so this would have skewed the figures downwards.

By contrast, the 2007 obesity rate presented by the Lancet study was 21.3%.

Ray D'arcy and Kathryn Thomas with Operation Transformation leaders. RollingNews.ie RollingNews.ie

Finally, let’s deal with one particularly eye-catching statistic included by The Lancet in the press release that accompanied the study:

Almost a fifth of the world’s obese adults (118 million) live in just six high-income English-speaking countries – Australia, Canada, Ireland, New Zealand, UK and USA.

It appears to be entirely accurate (the exact share is 18.4%), but perhaps gives a slightly misleading picture of Ireland’s share of those numbers. Frankly, it’s a bit silly.

Compared to the other six countries on that list (with the exception of New Zealand), our adult population is extremely small - around 3.44 million in 2014.

According to the Lancet study, 25.55% of those are obese – 880,000 people.

The number of obese individuals in New Zealand (whose adult population in 2013 was 3.4 million), is 990,000.

So you could easily take Ireland and New Zealand out of the equation, and be left with the following, equally accurate, assessment:

Almost a fifth (18.1%) of the world’s obese adults (116 million) live in just four high-income English-speaking countries – Australia, Canada, UK and USA.

You can check out the Lancet paper here, the data that goes with it, here, and the WHO figures on obesity, here.

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