Obesity linked to premature death

It is well known that being overweight can lead to health complications including diabetes, heart disease, stroke and cancer.

A recent study published in Lancet reports on a meta-analysis of 239 prospective studies published from 1970 to last year (median follow-up 13·7 years).  Of those 3 951 455 people in 189 studies were never-smokers without chronic diseases at recruitment who survived 5 years, of whom 385 879 died.   The investigators extracted their information from 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America.

They compared the risk of death to people's body mass index, or BMI, a measure of body fat that is calculated using height and weight.  They defined a BMI from 18.5 to 25 as normal, 25-30 as overweight, 30-35 as moderately obese and over 40 as severely obese.

In the study, the risk of dying before the age of 70 was 19 percent for men and 11 percent for women of normal weight.

But that risk jumped to 30 percent and 15 percent, respectively, for obese men and women.  The investigators found that overweight people die one year earlier than expected and that moderately obese people die up to three years prematurely.

The World Health Organization estimates that 1.3 billion adults worldwide are overweight, and 600 million more are obese. The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in all four continents. As common diseases such as heart disease, stroke, diabetes and cancer have been strongly associated to obesity, strategies to combat it are needed all around the globe.