Researchers identify two specific factors that are most important for reducing cancer risk – and it’s not BMI
Research shows that maintaining a slim waist while exercising regularly is the most effective at keeping cancer at bay.
One or the other is ‘insufficient’ to maximize cancer risk reduction, a study of more than 315,000 Britons found.
Experts say this shows why a ‘holistic’ approach is needed to cancer prevention, adding that even small lifestyle changes can pay off big time in the long run.
The World Cancer Research Fund’s analysis is the first to examine how these two factors combine to minimize cancer risk.
They compared the risk of cancer in people who met the World Health Organization (WHO) recommended levels for waist circumference – defined as less than 88 cm (35 inches) for women and 102 cm (40 inches) for men.
People were also assessed on whether they met the WHO guidelines for physical activity: 150 to 300 minutes per week of moderate-intensity exercise or 75 to 150 minutes of vigorous-intensity exercise per week.
During an average follow-up of eleven years, almost 30,000 people in the study developed cancer.
Those who did not meet the WHO guideline on waist circumference had an 11 percent increased risk of cancer, even if they followed the recommended amount of exercise.
Experts compared the risk of cancer in people who met the World Health Organization’s recommended levels for waist circumference – defined as less than 88 cm (35 inches) for women and 102 cm (40 inches) for men

Those who did not meet the WHO guideline on waist circumference had an 11 percent increased risk of cancer, even if they followed the recommended amount of exercise. Stock image
Similarly, those who didn’t reach the exercise threshold had a four percent increased risk of cancer, even if they were slim.
Failure to adhere to both guidelines increased the risk of cancer by 15 percent, according to findings published in the British Journal of Sports Medicine.
Lead researcher Professor Michael Leitzmann from the University of Regensburg in Germany said: ‘We are excited about the insights we have discovered regarding the interplay between waist circumference and physical activity in reducing cancer risk.
‘Our findings highlight the value of addressing multiple factors together, showing that both maintaining a recommended waist size and being physically active are critical to cancer prevention.
‘This research reinforces the importance of practical, achievable lifestyle changes that can have a meaningful impact on health over time.’
Previous studies have shown that exercise and a healthy diet full of fruits and vegetables reduce the risk of cancer.
But the authors concluded: ‘Adherence to both WHO guidelines for waist circumference and physical activity is essential for cancer prevention; Meeting just one of these guidelines is not enough.”
Examples of moderate activity include very brisk walking (6.5 km/h or faster), heavy cleaning such as window washing or brisk mopping, cycling at 10 to 20 km/h, or badminton.
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Examples of vigorous activities include walking, jogging at 6 miles per hour or faster, shoveling, fast cycling, a football match, basketball or tennis.
It comes as Cancer Research UK said it and its partners have committed £10 million to create new tools using AI and analytics to improve the early detection and prevention of cancer.
It says doctors will soon be able to predict the risk of developing cancer and provide personalized care, thanks to its five-year Cancer Data-Driven Detection program.
This could lead to the NHS offering more frequent cancer screening, or screening at a younger age, to people at higher risk, while those at lower risk could be spared unnecessary tests.
Dr. Helen Croker, assistant director of research and policy at the World Cancer Research Fund, said: ‘These findings underline the importance of taking a holistic lifestyle approach rather than focusing on a single factor to reduce cancer risk.
‘Maintaining a healthy weight and especially having a waist circumference within the recommended range and being physically active, along with eating a healthy diet, are all crucial steps in reducing the risk of cancer.
“People can start by making small, sustainable changes, such as incorporating regular exercise into the daily routine or choosing healthier food options.
“These gradual adjustments can make a big difference over time.”
The research follows recent analysis which found the number of people diagnosed with cancer in Britain will reach a record high of 3.4 million this year.