Weight Gain and Cancer Risk: New Findings

Research shows that gaining weight in adulthood can significantly raise cancer risk, with some individuals facing up to five times the risk, based on a study involving over 600,000 patients.

Obesity is linked to 13 different types of cancer and potentially correlates to another eight. However, the specific effects of when and how much weight individuals gain were less clear. To investigate, a team from Lund University in Sweden analyzed data related to weight and cancer diagnoses.

Presented at the European Congress on Obesity in Istanbul, the study monitored the weights of over 250,000 men and nearly 380,000 women multiple times between the ages of 17 and 60, tracking their cancer diagnoses until 2023.

The findings indicated that both higher initial weight in early adulthood and weight gained later in life correlated with increased cancer risk across various types.

Anton Nilsson, the study’s lead author and an associate professor at Lund, remarked, “The higher the starting weight and the greater the weight gain, the higher the cancer risk tended to be.”

Specifically, men who became obese before turning 30 had a fivefold increase in liver cancer risk, double the risk for pancreatic and kidney cancers, and a 58% higher risk for colon cancer compared to those who stayed slim. Similarly, women who became obese by 30 faced a four-and-a-half times greater risk of endometrial cancer, a 67% higher risk of pancreatic cancer, and a 76% increased risk for meningioma.

For those gaining weight later in life, the risks varied by gender. In women, weight gain after 30 strongly related to increased risks of endometrial cancer, postmenopausal breast cancer, and meningioma, conditions often linked to sex hormones. Weight changes also correlated with colon cancer rates in women.

In men, early weight gain before the age of 45 was more strongly associated with cancers like esophageal and liver cancer. Nilsson suggested that early weight gain might allow more time for biological factors like inflammation and raised insulin levels to affect vulnerable tissues.

Those who gained the most weight—averaging about 32 kg (or 5 stone)—were 7% more likely to develop cancer than those with lesser weight gain. Men in this group faced nearly three times the likelihood of developing liver cancer and over double the risk for esophageal cancer.

Furthermore, they had three times the risk for pituitary tumors and more than a 50% higher risk for renal cell carcinoma, gastric cardia, and colon cancers.

Women with significant weight increases also faced serious risks, with nearly four times the likelihood of endometrial cancer and double the risk for pituitary tumors. There were also increases in risks for renal cell carcinoma (91%), postmenopausal breast cancer (42%), meningioma (32%), and colon cancers (31%).

The study even noted that those who gained less weight still had higher cancer risks, underscoring the importance of maintaining a healthy weight.

“While our results don’t suggest specific interventions, they stress the value of keeping a stable, healthy weight throughout adulthood,” added Nilsson.

Megan Winter from Cancer Research UK commented on the findings, stating, “Overweight and obesity rank as the second leading cause of cancer in the UK. The government should take more action to help individuals achieve and maintain a healthier weight.”

She suggested that further measures could include curbing junk food advertising, making nutritious food more accessible, and promoting healthy eating habits more widely.