Being fit boosts longevity more than being thin, new research shows

Time to reassess your workout goals

Despite years of glorifying thinness, a review of research involving almost 400,000 people has determined that fitness rather than weight determines longevity. The research team joins other experts who insist fitness and overall health should be prioritised over weight.

Even though the skinny tea drinking, ‘clean’ eating centric and weight-focused fitness influencers of the past tried their best to convince us that thinner means healthier, new research has proven them oh so wrong.

Published in the British Journal of Sports Medicine, the comprehensive 2024 review analysed 20 previous studies to determine how fitness and body mass index (BMI) impact longevity.

The studies involved close to 400,000 people total, all of which were middle-aged or older, and 30 per cent were women. 

Each participant was classed as unfit or fit, depending on whether their endurance ranked in the lower 20 per cent or top 80 per cent of people of the same age and gender.

Going against years of skinny is best rhetoric, researchers found that actually, your fitness is more crucial to your health than your weight. 

The review highlighted that while the risk of an early death doubled or tripled in unfit people, regardless of their age or BMI, an aerobically fit person with obesity was around half as likely as an unfit person of normal weight to die prematurely. 

So clearly, our health priorities need to shift from weight to fitness if we’re aiming for longevity.

The study’s senior author, exercise physiologist Siddhartha Angadi told the Washington Post“This tells us that it’s much more important, all things considered, to focus on the fitness aspect” of health and longevity “rather than the fatness aspect.”

Our health priorities need to shift from weight to fitness if we’re aiming for longevity. Image: iStock

Shifting focus from BMIs

The authors concluded that ‘While increased risks of morbidity and mortality are associated with increased BMI’, interventions focused mainly on weight loss ‘are largely unsuccessful at maintaining long-term weight reduction and thus improved health outcomes.’

They say treatments focused on cardiovascular fitness rather than weight loss ‘may improve health outcomes while avoiding pitfalls associated with repeated weight loss attempts.’

While the demonisation of big bodies has pushed the message that overweight inherently means unhealthy, the researchers aren’t the first to emphasise that size doesn’t equate to health. 

In a report published in The Lancet Diabetes & Endocrinology journal last week, authors from the Global Commission on Clinical Obesity also recommended health professionals focus on patients’ health rather than weight-based BMIs when diagnosing obesity to ensure proper treatment. 

And while carrying excess weight can still put people at risk of issues including heart disease, high blood pressure and osteoarthritis, we do know that exercise helps to treat these conditions.

They say obesity treatments focused on cardiovascular fitness rather than weight loss ‘may improve health outcomes while avoiding pitfalls associated with repeated weight loss attempts.’ Image: iStock

Training for fitness instead of weight

Obesity can still be detrimental to your health, with men and women who were both obese and unfit being close to three times as likely to have died early than people who were fit and had a BMI within the normal range. 

But Angadi says “From a statistical standpoint, fitness largely eliminated the risk” of dying prematurely from obesity-related issues.

He and the team highlighted that according to the research, by just jumping from the lower 20th percentile of fitness to the 21st, people can easily go from being considered unfit to fit.

The exercise physiologist says moderate exercise, such as “brisk walks” should be enough to get you there. 

So while the current return of fashionable thinness may add to the pressure we feel to lose weight, if your focus is health and living a long life, fitness should be your priority.

Originally published as Being fit boosts longevity more than being thin, new research shows