“The size and rigor of this study provide a far better estimate of the link between excess weight and early death than the poorly designed, brain-dead research suggesting that no such link exists,” points out Dr. Jay Kenney, nutrition educator at the Pritikin Longevity Center (and never one to mince words).
Women, Men and Obesity
Recently published research on nearly 4 million people from 32 countries showed that being overweight definitely increases the risk of premature death (before age 70) when compared with being a healthy weight.
The study, in Lancet, had numerous strengths “compared to the schlocky, ‘it’s-okay-to-be-fat’ research that often gets top billing in the press,” notes Dr. Jay Kenney, Nutrition Research Specialist and Educator at the Pritikin Longevity Center.
In terms of scientific rigor, the Lancet study was top notch. To begin with, the authors deliberately excluded all people with factors that might affect body weight and could therefore skew the results. In the scientific community, they’re known as confounding factors. Weeded out were:
People who had smoked at any point in their lives
People who had been diagnosed with a chronic illness
People who died in the first five years of the study
To elaborate how the above groups confound a study’s results, let’s discuss smokers. People who smoke often weigh less. Many, in fact, are normal weight. But of course, they also tend to die prematurely. If they’re included in analyses looking for connections between body weight and deaths, the data could end up suggesting that being normal weight led to premature death when in fact smoking was far more likely the cause.
Similarly, people with a chronic illness like congestive heart failure often become thin, and their death rates are high. But it’s the disease that led to the thinness, not the other way around.
Not only the rigor but the size of the Lancet study was impressive.
It was carried out by 500-plus researchers from more than 300 institutions from around the world. It was coordinated by scientists at the University of Cambridge and funded by major public health organizations, including the British Heart Foundation and the U.S. National Institutes of Health.
It was a meta-analysis of 239 studies from four continents: Asia, Australia, Europe, and North America. (Meta-analyses pool data from many smaller studies with the goal of arriving at more reliable overall conclusions.) From the 239 studies, there were 10.6 million people. The scientists narrowed their research down to 3.9 million people after excluding smokers, people with chronic disease, or people who died within five years after the study had began.
Weight was measured in terms of body mass index (BMI), which relates weight to height. Generally, a BMI in the range of 18.5 to 25 is considered normal, 25 to 30 is overweight, and higher than 30 is obese. Calculate your BMI here.
Key conclusions of the Lancet study were:
Obesity and Early Death
Being obese does increase the risk of early death, and that risk increases with every extra pound of weight.
Deaths from heart disease, stroke, and respiratory disease were strongly increased for people with a BMI over 25. Deaths from cancer were moderately increased.
For overweight or obese people in Europe and east Asia, every additional five BMI points over the normal range was associated with an additional 39% increase in risk of death. The risk was slightly lower in the United States and Australia.
“Obesity is second only to smoking as a cause of premature death in Europe and North America,” said co-author Dr. Richard Peto, Professor of Medical Statistics and Epidemiology at the University of Oxford.
“Smoking causes about a quarter of all premature deaths in Europe and in North America…But overweight and obesity now cause about 1 in 7 of all premature deaths in Europe and 1 in 5 of all premature deaths in North America.”
Men and Obesity
“We found that men who were obese were at much higher risk of premature death than obese women. This is consistent with previous observations that obese men have greater insulin resistance, liver fat levels, and diabetes risk than women,” stated lead author Dr. Emanuele Di Angelantonio, Academic Director of Public Health at the University of Cambridge.
Overall, the risk of premature death among people who were overweight or obese was about three times as great in men as in women.
Youth and Obesity
The data were worrisome for younger ages, too.
Notably, for people ages 35 to 49, every additional five BMI points over the normal-weight range was linked with an additional 52% increase in risk of premature death.
This meta-analysis pooled its results from observational studies, also known as prospective studies, which means that people were simply watched over a period of time. Observational studies cannot establish cause-and-effect, as randomized controlled trials can.
“But the size and rigor of this study provide a far better estimate of the link between excess weight and early mortality than the poorly designed, brain-dead research suggesting that no such link exists,” points out Dr. Kenney, nutrition educator at Pritikin (and never one to mince words).
Men and Obesity | Summing Up
The media often feeds us sensationalism. The more dramatic a headline, the more money-making clicks it generates. The media also feeds us news we want to hear. Headlines like “It’s okay to be fat” certainly fall into this category.
So it’s no surprise that the media largely ignored this recent study in Lancet, as impeccable as its research was. It told us what we don’t like to hear, but what we know is true.
It also affirmed what a mountain of data over the past several decades has found: Being overweight or obesity is linked with early death. Moreover, in this Lancet study the link occurred worldwide, and at all levels of weight, and among both men and women. But especially hard hit were men.
“The media may ignore this data, but the doctors, dietitians, exercise physiologists and other faculty at the Pritikin Longevity Center certainly do not,” sums up Dr. Kenney.
“It is data that assures all people who come to Pritikin that yes, they’re doing the right thing. Bottom line: When you watch your weight by eating a healthy diet like the Pritikin Eating Plan and exercising daily, you’re not only living better by protecting yourself from chronic conditions like heart disease, you’re very likely living longer.”