Individuals categorized as fit, even if overweight or obese, did not exhibit a notable rise in cardiovascular disease or overall mortality rates.
As obesity rates in the United States, measured by body mass index (BMI), continue to rise, so too have efforts to promote weight loss, including the advent of a new generation of weight-loss medications. However, a systematic review and meta-analysis published today in the British Journal of Sports Medicine reveals that cardiorespiratory fitness is a more powerful predictor of cardiovascular disease and overall mortality than BMI.
The researchers found that fit individuals across all BMI categories had statistically similar risks of death from all causes of cardiovascular disease.
By contrast, unfit individuals in all BMI categories showed two- to three-fold higher risks of both all-cause and cardiovascular disease mortality compared with normal-weight fit individuals. In fact, obese fit individuals had a significantly lower risk of death compared to normal-weight unfit individuals.
Fitness Over Fatness: Key Insights
“Fitness, it turns out, is far more important than fatness when it comes to mortality risk,” said Siddhartha Angadi, associate professor of exercise physiology at the University of Virginia School of Education and Human Development and corresponding author of the study. “Our study found that obese fit individuals had a risk of death that was similar to that of normal weight fit individuals and close to one-half that of normal weight unfit individuals.
“Exercise is more than just a way to expend calories. It is excellent ‘medicine’ to optimize overall health and can largely reduce the risk of cardiovascular disease and all-cause death for people of all sizes.”
The researchers reviewed 20 studies with a total sample size of 398,716 adults from multiple countries. About one-third of the participants in the studies were females, an increase of nearly three-fold from previous studies. In the majority of studies, individuals were classified as fit if their exercise stress test score (estimated or directly measured VO2max) placed them above the 20th percentile within their age group.
Obesity is associated with a series of health conditions and weight loss has long been seen as the way to reduce the impact of those conditions. But weight loss is challenging and failing to keep weight off can bring other risks.
The Risks of Weight Cycling and Benefits of Fitness
“Most people who lose weight regain it,” said Glenn Gaesser, professor at Arizona State University and co-author of the study. “Repetitive cycles of losing and gaining weight—yo-yo dieting—is associated with numerous health risks comparable to those of obesity itself. Improving cardiorespiratory fitness may help avoid the adverse health effects associated with chronic yo-yo dieting.”
Approximately 20% of US adults meet the physical activity guidelines set by the U.S. Department of Health and Human Services. Current guidelines recommend adults perform a minimum of 150 minutes per week of moderate-intensity physical activity or 75 minutes of vigorous physical activity along with muscle strengthening for two days a week. For those who find themselves in the bottom 20th percentile of cardiorespiratory fitness, beginning any kind of aerobic exercise could have a big impact.
“The largest reduction in all-cause and cardiovascular disease mortality risk occurs when completely sedentary individuals increase their physical activity modestly,” Angadi said. “This could be achieved with activities such as brisk walking several times per week with the goal of accumulating approximately 30 minutes per day.”
The researchers note that the study examines data from large epidemiological studies and recommend that it is time to independently assess the value of a fitness-based approach rather than a weight-loss approach in obese individuals to optimize health outcomes.
Reference: “Cardiorespiratory fitness, body mass index and mortality: a systematic review and meta-analysis” by Nathan R Weeldreyer, Jeison C De Guzman, Craig Paterson, Jason D Allen, Glenn A Gaesser and Siddhartha S Angadi, 13 November 2024, British Journal of Sports Medicine.
DOI: 10.1136/bjsports-2024-108748
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
26 Comments
How can you be fit and obese at the same time?
“In the majority of studies, individuals were classified as fit if their exercise stress test score (estimated or directly measured VO2max) placed them above the 20th percentile within their age group.” Of course, this means that being fit is a relative state, compared to the general population. If you use our current out-of-shape, sendentary population, there is a low bar for fitness, and being in the top 20th percentile isn’t saying much.
Yeah, this “study” is set on some quite arbitrary foundations.
This doesn’t address the effects of excess wear on the joints in overweight people your health will suffer if your knees and hips give out at 50.
I’ve known this for decades. Its nice to see it verified.
Being fit actually preserves the joints.
Its repetitive motion like jogging, over exercise for sport, playing on flat hard surfaces and such that wears them out.
At 63 I’m fit with good joints. What’s fit? On a lark I’ll climb a local mountain.
You can’t
By staying physically active. By exercising or walking three or more times a week.
I know obese runners that run in races. It happens.
Cardio respiratory health is not how much fat you carry. Those are different things. Just as you can be skinny and unable to walk up the stairs due to the exertion, so are you able to still accumulate fat even if you are very active.
Have you never seen a linebacker in the NFL? Most of those guys have BMIs that would categorize them as obese and yet they are QUITE fit! The two are not mutually exclusive.
There are plenty of NFL players who are overweight but appear to be very fit and healthy. I kept thinking about them while reading this article.
I’m not overweight and I’m in very poor health. I used to be overweight and I lost 30 pounds and I actually feel worse than when I was overweight.
I see underweight people as suffering from an illness and weak, the idea of skinny been beautiful cones from fashion designers looking for young teen look. Many people suffer from such ideas. During the Victorian times overweight women were considered beautiful. And overweight men successful.
I see underweight people as suffering from an illness and weak, the idea of skinny been beautiful is based from fashion designers looking for young teen look. Many people suffer from such ideas. During the Victorian times overweight women were considered beautiful. And overweight men successful.
Based on the description of this meta-analysis, it unsurprisingly appears to confirm that fitness matters but more importantly, this is more of an indictment on how poor of a measurement that the use of BMI is for measuring an individual’s overall health. There are many people that have an athletic build which includes more muscle and less body fat composition that would be considered obese by a BMI calculation. Additionally, there are individuals with a normal BMI but have less musculature but more underlying visceral fat. All in all, BMI gives no indication of a person’s body composition and fitness level and does not make any adjustments based on other possible variables such as sex or race/ethnicity.
Race and or ethnicity doesn’t play apart in it. For example. Sub-Saharan African women are the same size as European women but smaller than american and black american women. The bmi is bad because they don’t measure fat%. Which is way better of an indicator than just weight mass. This study sounds like it was produced by people that have very little understanding of how the body works . The difference between fat and weight. And that thinnnes and or leanness is basically determined by what (more importantly how much) you consume. Basically this studied by liberal researchers (im a liberal btw) and most of us don’t have a decent understanding of health and fitness. There are better studies explaining why bmi is false, but how fat (to which you can be fat and still fit within bmi standards) can massively effect your health (cardiovascular, diabetes, etc…).
Where did you earn your MD or PHD? Or maybe you’re just another MAGA knucklehead who doesn’t believe in science.
There is no such thing as a fit obese person. This is pro obesity propaganda. Fats should be euthanized.
So should mean people
People who think people should be euthanized, should be euthanized.
Fatty
Same with trolls.
Sounds like you have some personal issues that you need to sort out.
Obesity shows that a person has perfect metabolism and efficiently converts food energy. Lean people just waist away calories. Lack of movement is a different story
Actually being obese shows the exact opposite of that. Some people are obese because their body’s Metabolism isn’t working properly (autoimmune disorders, thyroid, even Metabolism disorders). See this is the issue with this topic. People are severely ignorant to the body and how it actually works in sequence with health and fitness.
Actually being obese shows the exact opposite of that. Some people are obese because their body’s Metabolism isn’t working properly (autoimmune disorders, thyroid, even Metabolism disorders). See this is the issue with this topic. People are severely ignorant to the body and how it actually works in sequence with health and fitness.
Fat & Fit, baby