New research funded by the World Cancer Research Fund found people needed to exercise and keep their weight down if they were to reap the maximum benefits of keeping cancer at bay.
The large study on more than 315,000 people is the first to investigate how both actions combine to reduce cancer risk.
The study examined 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 – and/or those who met guidelines for exercise, and compared them with those who did not.
WHO recommends 150 to 300 minutes per week of moderate-intensity exercise, 75 to 150 minutes of vigorous-intensity exercise, or an equivalent combination of weekly moderate and vigorous-intensity aerobic activity.
Examples of moderate-intensity activity include very brisk walking (6.4kmh or faster), heavy cleaning such as washing windows or fast mopping, cycling at 16-19kmh, or badminton.
Vigorous activity examples include hiking, jogging at 9.7kmh or faster, shovelling, fast cycling, a football game, basketball or tennis.
During an average follow-up of 11 years, almost 30,000 people in the study developed cancer.
Researchers found that people not meeting the WHO guideline on waist circumference had an 11% increased cancer risk, even when they did enough exercise.
Similarly, people not achieving the guidelines for exercise had a 4% increased risk of cancer, even if they were lean around the waist.
Not keeping to either guideline increased people’s risk of cancer by 15%.
Previous studies have shown that exercise and a healthy diet of fruit and vegetables cuts the risk of cancer.
Writing in the British Journal of Sports Medicine, the team said: ”Adherence to both WHO guidelines for waist circumference and physical activity is essential for cancer prevention; meeting just one of these guidelines is insufficient.”
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.”
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.”
A separate WHO report has said people are at increased risk of metabolic complications such as type 2 diabetes if their waist circumference is higher than 80cm (31 inches) for women and 94cm (37 inches) for men, while the increase was “substantial” if over 88cm and 102cm respectively. – dpa
