Is obesity linked to a higher risk of colorectal cancer?

Adults with obesity appear to have a greater likelihood of developing colorectal cancer compared to those without obesity, according to data drawn from millions of individuals across multiple studies ¹. This connection holds across different populations and study designs. Additionally, the evidence suggests that men with obesity may face a higher increase in risk than women with obesity, though the reason for this difference is not fully understood ².

We did not find any studies that showed obesity lowers risk or has no association. The pattern across all reviewed data points in one direction: higher body weight is tied to a higher chance of this type of cancer. However, we cannot say obesity causes colorectal cancer, only that the two are connected in the data we’ve reviewed.

This does not mean everyone with obesity will develop colorectal cancer, nor does it mean people without obesity are free from risk. But the weight of the evidence we’ve seen so far suggests that carrying excess body fat may be one factor among many that influences risk.

If you’re concerned about your risk, maintaining a healthy weight through balanced eating and regular movement may help reduce your chance — not because it guarantees protection, but because the patterns we’ve seen suggest it’s one part of a larger picture.