Excess weight, obesity more deadly than previously believed
A new study from the University of Colorado Boulder, and published in the journal Population Studies, has found that the risk of death from excess weight or obesity is much higher than previously believed, with mortality rates increased by between 22% to 91%.
The research challenges the “obesity paradox,” which suggests that only extremely high levels of excess weight are associated with increased mortality risk. The study analysed data from nearly 18,000 people and found that using body mass index (BMI) to study health outcomes can bias findings, potentially leading to underestimates of the consequences of living in an environment where unhealthy food is cheap and sedentary lifestyles are the norm. The study estimates that about one in six U.S. deaths are related to excess weight or obesity.
The research found that a full 20% of people classified as having a “healthy” weight had previously been in the overweight or having obesity category, and that these individuals had a substantially worse health profile than those in the “healthy” category whose weight had been stable. The study also found that the health and mortality consequences of high BMI are duration-dependent, meaning that people who have spent most of their lives at a low BMI but have recently gained weight may have better health profiles than those who have had overweight or obesity for most of their lives.
The study’s author, Ryan Masters, hopes that the research will alert scientists to be “extremely cautious” when making conclusions based on BMI, and will draw attention to the public health crisis of an “obesogenic” environment in the U.S. Masters noted that the prospects of healthy ageing into older adulthood do not look good for groups born in the 1970s or 1980s who have lived their whole lives in this obesogenic environment. The study estimates that about 16% of U.S. deaths are related to excess weight or obesity, a figure that is eight times higher than previous research had suggested.
