Context (TH): Obesity rates are increasing globally, including in India.
A 2022 study in The Lancet found that 9.8% of Indian women and 5.4% of men are obese.
Obesity is linked to higher risks of heart disease, diabetes, and colorectal cancer (CRC).
Obesity & Fat distribution
Obesity is typically defined using the body mass index (BMI), which considers height and weight.
A BMI of 25 kg/m2 or higher indicates overweight, while 30 kg/m2 or higher indicates obesity.
However, BMI doesn’t account for how fat is distributed in the body. Scientists use measures like waist circumference, hip circumference, and waist-to-hip ratio to assess fat distribution.
Colorectal Cancer (CRC)
CRC refers to cancers of the colon or rectum.
CRC incidence in India is relatively low, but survival rates after diagnosis are under 40%.
Indian CRC patients are often young and diagnosed at advanced stages, according to a 2017 study.
Who is at risk of colorectal cancer (CRC)?
Scientists identified four body shape groups:
PC1 (generally obese).
PC2 (tall with a low waist-to-hip ratio).
PC3 (tall with central obesity).
PC4 (athletic body shape).
PC2 and PC4 individuals showed no significant association with CRC risk.
A gene called AKT was associated with higher colorectal cancer (CRC) risk in generally obese individuals.
Another gene, RAF1, was linked to CRC risk in tall and centrally obese individuals.
