Keeping a slim waist while exercising regularly is most effective for keeping cancer at bay, research suggests.
One or the other is ‘insufficient’ to maximise the reduction in cancer risk, a study involving more than 315,000 Britons found.
Experts said it shows why a ‘holistic’ approach is needed to cancer prevention, adding that even small lifestyle changes can reap big rewards in the long term.
The analysis by the World Cancer Research Fund is the first to examine how these two factors combine to minimise cancer risk.
They compared the chances of cancer in people who met the World Health Organisation (WHO) recommended levels for waist circumference – defined as less than 88cm (35ins) for women and 102cm (40ins) for men.
People were also assessed over whether they met WHO guidelines for exercise – 150 to 300 minutes per week of moderate-intensity exercise or 75 to 150 minutes of vigorous-intensity exercise a week.
During an average follow-up of 11 years, almost 30,000 people in the study developed cancer.
Those who did not meet the WHO guideline on waist circumference had an 11 per cent increased cancer risk, even when they undertook the recommended levels of exercise.
Similarly, those who did not meet the exercise threshold had a four per cent increased risk of cancer, even if they were lean around the middle.
Not keeping to either guideline increased people’s risk of cancer by 15 per cent, according to the findings published in the British Journal of Sports Medicine.
Lead researcher, Professor Michael Leitzmann, from the University of Regensburg in Germany, said: ‘We’re excited about the insights we’ve uncovered 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 for 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 fruit and vegetables cuts 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 insufficient.’
Examples of moderate activity include very brisk walking (4mph or faster), heavy cleaning such as washing windows or fast mopping, cycling at 10-12mph, or badminton.
Vigorous activity examples include hiking, jogging at 6mph or faster, shovelling, fast cycling, a football game, basketball or tennis.
It comes as Cancer Research UK said it and its partners were committing £10 million to create new tools using AI and analytics to improve early cancer detection and prevention.
It said doctors could soon be able to predict an individual’s chances of getting cancer and offer personalised help, thanks to the five-year Cancer Data-Driven Detection programme.
This could lead to the NHS offering more frequent cancer screening, or screening at a younger age, to those at higher risk, whilst 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 underscore the importance of a holistic lifestyle approach instead of focusing on a single factor to reduce cancer risk.
‘Maintaining a healthy weight and, in particular, having a waist circumference within the recommended level and being physically active, along with eating a healthy diet, are all crucial steps to reduce cancer risk.
“People can start by making small, sustainable changes like incorporating regular movement into daily routines or choosing healthier food options.
‘These gradual adjustments can add up to a big difference over time.’
The research follows a recent analysis which warmed number of people living with cancer in the UK will hit a record high of 3.4 million this year.
