Men were found to have a 19% risk with women at 11%.
Advertisement
According to World Health Organisation (WHO) estimates 1.3 billion adults worldwide are overweight and a further 600 million are obese.
The information, described as the largest-ever pooled dataset on being overweight and mortality, was gathered from 239 large studies conducted between 1970 and 2015 in 32 countries in North America, Europe, Australasia, and southern and eastern Asia. The risks of coronary heart disease, stroke, respiratory disease and cancer are all increased.
Scientists say though the reasons behind the trend are unclear, the study supports others that suggest obese men are at higher risk of diabetes and have higher levels of risky liver fat.
“The results highlight that even slight increase in BMI can cause harm”, says Dr. Emanuele Di Angelantonio, a lecturer at the University of Cambridge and lead author of the study.
The data also found differences between men and women, with the risk to men in general three times greater than for women when they are overweight or obese.
According to Public Health England, more than 60% of adults (16 years old or older) in England were overweight or obese in 2014, and about 1 in 4 of adults in England were obese. At entry to the study all were aged between 20 and 90 years old, and were non-smokers who were not known to have any chronic disease when their BMI was recorded.
Instead, the study pointed to evidence that the risk of dying before your 70th birthday grows “steadily and steeply” along with an expanding waistline. “This is consistent with previous observations that obese men have greater insulin resistance, liver fat levels and diabetes risk than women”.
To rule out the impact of other mortality risks, the team excluded current or former smokers, those who had chronic disease at the beginning of the study, and those who died within the first five years – and were left with a sample group of 3.9 million adults. They looked at participants’ body mass index (BMI)-an indicator of body fat calculated by dividing a person’s weight in kilograms by their height in meters squared (kg/m2).
Obese adults make up 20% of the population in Europe and 31% in North America.
“Obesity is second only to smoking as a cause of premature death in Europe and North America”, says co-author Professor Sir Richard Peto, University of Oxford, Oxford, UK.
Being overweight or obese is linked to a higher risk of dying prematurely than being normal weight and the risk rises sharply as the extra pounds pile on, scientists said on Wednesday.
And the links between obesity and death were strongest for men. The authors say that assuming that the associations between high BMI and mortality are largely causal, if those who were overweight or obese had WHO-defined normal levels of BMI, then the proportion of premature deaths that would be avoided would be about one in 7 in Europe and one in 5 in North America.
Advertisement
However, the results showed that participants with a normal BMI (18.5-25) had the lowest risk of dying before the age of 70. With randomized trials in this realm problematic, big data sets are what researchers have, they said. From a public health standpoint, I think the public needs to be aware of the effects of excess body weight, which include higher risk of Type 2 diabetes, cancer, and cardiovascular disease.
