According to a new study, obesity is known to raise the risk of colorectal cancer. The reason for this is that many patients lose weight unintentionally before being diagnosed with colon cancer. The researchers noted that when studies only include body weight at the time of diagnosis, the real relationship between obesity and colon cancer risk is concealed.

The current study shows that unintentional weight loss can be a precursor to colorectal cancer. The researchers explained that obesity puts people at risk for a wide range of cancers. They also revealed that, as per the data from previous studies, the risk of colon cancer in obese people is one-third higher than that of people of normal weight.

Dr. Hermann Brenner, an epidemiologist and prevention expert at the German Cancer Research Centre, noted that these studies have not taken into account that many patients start losing weight in the years before their colorectal cancer is diagnosed. Hence, no relationship between body weight and the risk of colorectal cancer can be established based on body weight at the time of diagnosis.

However, in the study, when the researchers looked at the participants` earlier body weight, they found a strong correlation between overweight and the probability of developing colorectal cancer. They noted that the relationship was more pronounced before 8 to 10 years of diagnosis. 

(Source: https://health.economictimes.indiatimes.com/news/industry/study-finds-obesity-as-risk-factor-for-colorectal-cancer/100006265)