Health knowledge and news provided by doctors.

What is the Best BMI for Living Longest? The Answer Will Surprise You!

Tim Boyer's picture
Study shows low BMI not always better for living longer

Lose weight and live longer! That’s one of the reported benefits of weight loss, and more is better…or is it? A new study reveals the true best BMI for living longer.


We’ve all heard that losing weight and reaching a low BMI is one of the biggest predictors of living a longer life. But just how low should you go if your goal is truly to live your longest? According to Dr. Oz, the BMI really isn’t that accurate and a recent study this year argues that your BMI is a deeply flawed measure of health.

According to a news release from the University of Copenhagen researchers have made a startling discovery that is contrary to what we would expect. Rather than the recent obesity epidemic leading to a growing trend of fat-related deaths, they found that the excess risk of premature death associated with obesity has actually decreased over the past 40 years!

Referred to within the medical community as “All-cause mortality,” obesity-associated death was higher in obese individuals than in normal weight individuals in 1976-78, but not in 2003-13! In other words, claims of thinness with longevity do not pan out when the death-cause numbers are crunched during analysis.

“The increased risk of all-cause mortality associated with obesity compared to normal weight decreased from 30% 1976-78 to 0% in 2003-13,” says principal investigator Dr. Shoaib Afzal, Herlev Hospital, Copenhagen University Hospital, Denmark.

What is a BMI?

Body Mass Index (BMI) is a classification used by health providers to put a measurable number on whether someone is of normal weight, overweight or obese. A BMI is calculated as weight in kilograms divided by height in meters squared.

• A BMI of 18.5-24.9 is considered normal weight

Follow eMaxHealth on YouTube, Twitter and Facebook.
Please, click to subscribe to our Youtube Channel to be notified about upcoming health and food tips.

• A BMI of 25-29.9 represents overweight

• A BMI of 30 or greater represents obesity

So Just What is the Optimal BMI for Lowest Mortality?

Looking at BMIs associated with the lowest all-cause mortality in three cohort studies from Copenhagen ranging from 1976 to 2013, the researchers found that the trend was a slowly increasing BMI associated with longevity.

“The optimal BMI for the lowest mortality increased from 23.7 in 1976-78, through 24.6 in 1991-94, to 27 in 2003-13, while individuals with a BMI below or above the optimal value had higher mortality,” adds Shoaib Afzal.

“Compared to the 1970’s, today’s overweight individuals have lower mortality than so-called normal weight individuals. The reason for this change is unknown. However, these results would indicate a need to revise the categories presently used to define overweight, which are based on data from before the 1990’s” says senior author Clinical Professor Børge G. Nordestgaard, University of Copenhagen and Copenhagen University Hospital.

However, the researchers point out that their data should not be interpreted as suggesting that so-called normal weight individuals should eat more to become overweight. Rather, that perhaps “…overweight people need not be quite as worried about their weight as before,” adds Professor Nordestgaard.

Reference: University of Copenhagen―“Obesity less dangerous than 40 years ago

Image courtesy of Pixabay