Overview

• A systematic review and meta-analysis of 37 prospective studies published in the International Journal of Cancer examined birthweight and body mass index across early life stages.
• Each 5 kg/m2 increase in BMI at ages 18–25 corresponds to a 12% higher risk of developing colorectal cancer in adulthood, with adolescents and children also facing elevated risks.
• Every additional kilogram at birth was associated with a 9% increase in long-term colorectal cancer risk, highlighting birthweight as an independent factor.
• The research was conducted under the World Cancer Research Fund International’s Global Cancer Update Programme to fill gaps in understanding the early origins of colorectal cancer.
• With over 2,600 new cases diagnosed annually in UK adults under 50, experts say early-life weight management should become a key focus of cancer prevention strategies.