Obesity and cancer: those who gain weight before the age of 30 risk up to five times more
Presented at the European Congress in Istanbul, a Swedish maxi-analysis of more than 600,000 people followed for decades: increase in liver, endometrial, pancreatic, colon and kidney cancers in particular
by Francesca Cerati
Key points
It is not only the weight achieved in adulthood that counts. It matters when you gain weight, how quickly the kilos pile up, and how long the body remains exposed to obesity. This is the conclusion of one of the most comprehensive analyses ever conducted on the relationship between excess weight and cancer, presented at the European Congress on Obesity (Echo 2026) currently taking place in Istanbul.
The study, co-ordinated by researchers Anton Nilsson and Tanja Stocks from the University of Lund, Sweden, followed over 630,000 people - more than 251,000 men and almost 379,000 women - reconstructing body weight trends from the ages of 17 to 60 and relating them to cancer occurrence until 2023.
The risk of developing different types of cancer
The results show a definite relationship: the greater the weight gain during adult life, the greater the risk of developing various types of cancer already associated with obesity. Comparing the 20 per cent of people who accumulated the most weight with the 20 per cent who accumulated the least, the overall cancer risk increased by 7 per cent in men and 17 per cent in women. But it is on obesity-related cancers that the heaviest figures emerge: the risk increases by 46% in men and 43% in women.
For some malignancies, the increases are particularly marked. In men, those who gain the most weight have a 2.67 times higher risk of liver cancer and a more than double the risk of adenocarcinoma of the oesophagus. In women, on the other hand, the most striking figure concerns endometrial cancer, with an almost fourfold increased risk compared to those who maintain a more stable weight over time.
The study also shows significant increases for colorectal cancer, renal carcinoma, gastric cardia and pancreatic cancer, as well as a possible association with neoplasms hitherto less clearly linked to obesity, such as pituitary tumours, certain lymphomas and malignant melanoma.
