Korean J Fam Pract.  2025 Mar;15(1):54-60. 10.21215/kjfp.2025.15.1.54.

Analysis of the Associations among Obesity, Exercise Habits, and Weight Change with Colorectal Cancer Risk: Utilizing Customized Data from the National Health Insurance Service

• Ko Y
• Kim Yj

• KMID: 2565940
• DOI: http://doi.org/10.21215/kjfp.2025.15.1.54

Abstract

Background
Although numerous studies examined the association between obesity and colorectal cancer, comparatively less research has focused on the relationship between weight change and physical activity.
Methods
This study used health check-up data from the National Health Insurance Service. Participants aged 20–79 years who underwent health check-ups between 2004 and 2007 and again 10 years later were included. Differences were analyzed by dividing the weight change into groups that increased or decreased by 5%, 5%–20%, and 20% or more.
Results
Among men, a 5%–20% increase in body weight was significantly associated with a higher risk of colon cancer (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.05–1.52), even among those who exercised on at least 3 days a week. In contrast, women who had undergone a weight loss of more than 20% of their body weight were found to have a significantly reduced risk of colon cancer (HR, 0.69; 95% CI, 0.50–0.93). However, women who reduced their exercise frequency from 3 or more days per week to less than 3 days per week experienced a weight gain of 20% or more, which was associated with a higher risk of developing colorectal cancer (HR, 1.82; 95% CI, 1.07–3.12).
Conclusion
These findings highlight the association between recent increases in colon cancer incidence and weight management, emphasizing the importance of maintain a healthy weight in mitigating obesity-related cancer risk.

Keyword

Obesity; Colonic Neoplasms; Body Weight Changes; Body Mass Index; Exercise