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The ‘obesity paradox’ debunked, according to new study

Being overweight or obese really can shorten lives – and cause people to spend their later years in misery, reveals a new study. 

Many studies have echoed a counter-intuitive finding: that obese people live longer than those with lower weights.

Most of this research looked at how long these people lived after being diagnosed with a disease, and found that higher BMIs were linked to longer survival times.

But new research from Northwestern University has debunked that myth by analyzing – for the first time – subjects’ entire lives and finding that obese and overweight people do not live longer, they just tend to get diagnosed earlier.  

New research from Northwestern University has debunked the myth that obese people live longer than thin ones (file image)

Obesity’s effects are worse for women, with those obese in their 40s and 50s almost twice as likely to suffer a heart attack, stroke, heart failure or death from cardiovascular disease.

The risk for men in the same boat increases by two thirds, according to the 50 year analysis of almost 200,000 people.

Being overweight increased the odds of any of these four outcomes for women and men by a third and a fifth respectively.

Dr Sadiya Khan, an assistant professor of medicine, said the findings debunk the ‘obesity paradox’ – which states carrying too many pounds helps patients with potentially fatal illnesses live longer.

She said: ‘A healthy weight promotes healthy longevity or longer healthspan in addition to lifespan, so that greater years lived are also healthier years lived. It’s about having a much better quality of life.’

Normal weight middle-aged men survived 1.9 years more than those who were obese – and six years longer than the morbidly obese. But there was no significant advantage over overweight men.

But normal weight middle-aged women lived 1.4 and 3.4 years longer than overweight counterparts respectively – and six years more than the morbidly obese.

Dr Khan, a cardiologist at Northwestern University in Chicago, said: ‘The obesity paradox caused a lot of confusion and potential damage because we know there are cardiovascular and non-cardiovascular risks associated with obesity.

‘I get a lot of patients who ask, ‘Why do I need to lose weight, if research says I’m going to live longer?”.


Not smoking, maintaining a healthy weight and drinking in moderation could add up to 12 years to your life, research revealed in July last year.

While women who follow a healthy lifestyle can expect to have an extra dozen years, men can extend their life by 11, a study found.

On its own, drinking alcohol in moderation adds seven years to your life. These additional years are also free of disability, the research adds.

Never smoking and not being obese gives you an extra four-to-five disability-free years, the study found.

Study author Mikko Myrskylä from the Max Planck Institute for Demographic Research in Rostock, Germany, said: ‘A moderately healthy lifestyle is enough to get the benefits. 

‘Avoiding becoming obese, not smoking, and consuming alcohol moderately is not an unrealistic goal.’ 

‘I tell them losing weight doesn’t just reduce the risk of developing heart disease – but other diseases like cancer. Our data show you will live longer and healthier at a normal weight.’

The large-scale study of almost 200,000 people aged 40 to 59 found the odds of having a stroke, heart attack, heart failure or cardiovascular death were 85 and 67 percent higher in obese women and men respectively.

And they were 32 and 21 per cent more in overweight women and men respectively. The increased risks were in comparison to their normal weight peers.

Dr Khan said it shows the obese don’t live longer than slimmer people with heart disease – they’re just diagnosed at a younger age.

She said keeping in shape can postpone cardiovascular disease – and reduce the overall risk. A healthy weight ‘lengthens your lifespan and ‘healthspan’.’

The study, published in JAMA Cardiology, said the lives of obese people are shorter on average – with a greater proportion of them spent with cardiovascular disease.

Overweight peoplle also have a higher risk of developing cardiovascular disease – and more years living with it.

It is the first study of its kind to provide a lifespan perspective on the risks of developing cardiovascular disease and dying after a diagnosis of cardiovascular disease for normal weight, overweight and obese individuals.

Obesity is defined as having a Body Mass Index (BMI) of 30 to 39.9; overweight is 25 to 29.9. BMI is a person’s weight divided by his or her height.

An overweight individual, who is 5’4′ and weighs 160 pounds, for example, would be considered overweight; a 5’4′ person who weights 190 pounds is considered obese.

The study examined data from 190,672 examinations of individuals with an aggregate of 3.2 million years of follow-up.

All of the participants were free of cardiovascular disease at the start and had objectively measured height and weight to assess BMI.

They were followed up over a period that spanned from 1964 to 2015. The researchers assessed cardiovascular disease cases overall and by type – including coronary heart disease, stroke, heart failure and deaths from all causes.

The ‘obesity paradox’ says overweight people with certain medical conditions such as diabetes, kidney disease, and high blood pressure, are protected from death.

The theory is a person with cardiovascular disease and fat stores will perhaps outlive someone who does not.

But in recent years research has been growing that the idea is a myth. Lat year a smaller US study of more than 30,000 people over 50 found those who were obese were not more likely to survive heart disease in old age.

Earlier this week Cancer Research UK warned seven in 10 ‘millennials’ – those born between the early 1980s and mid-1990s – will be overweight by the time they are 35, making them the heaviest generation since records began.

By contrast, just five in 10 baby boomers – those born between 1945 and 1955 – were overweight or obese at the same age.


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