Weight gain increases the risk of cancer, research suggests – casting doubt on the idea that people can be “fat but fit”.

Weight gain can lead to an 11 percent higher risk of certain cancers, including colon, breast and pancreatic cancer.

Being overweight or obese is known to increase the risk of at least thirteen types of cancer.

But experts are less clear about whether people’s weight is the biggest problem or whether their obesity-related diseases, including cardiovascular disease and type 2 diabetes, are the biggest problem.

Now, a study of nearly 600,000 people has found that every five-point increase in body mass index (BMI) is associated with an 11 percent higher risk of obesity-related cancers, even among people without cardiovascular disease or type 2 diabetes.

This casts doubt on the theory that one can be “fat but fit”: carrying excess weight without heart problems or diabetes, with little impact on disease risk.

It found that a subgroup of 344,000 people from Britain included in the study had a 23 percent higher risk of obesity-related cancers if they were overweight or obese, compared with those of normal weight, even if they were not. Cardiovascular disease.

Too much weight can lead to inflammation in the body or an excess of the hormone insulin, which can lead to the development of tumors.

Dr Heinz Freisling, lead author of the study from the International Agency for Research on Cancer, said: “We have often talked about people who are overweight but metabolically healthy, that is they do not have type 2 diabetes or cardiovascular disease . Illnesses. .”

“But this research shows that these people are still at increased risk for cancer and may therefore want to maintain a healthy weight.”

“But their risk increases if they also suffer from cardiovascular disease.”

The study, published in the journal BMC Medicine, focused on 13 obesity-related cancers.

These include breast cancer only in postmenopausal women, as well as ovarian and uterine cancer, which can be caused by hormones produced in body fat when people are overweight.

Types of cancer also include colon, pancreatic, kidney and esophageal cancer.

The risk of developing these obesity-related cancers was 11 percent higher for every five-point increase in BMI, but increased by 17 percent for people with cardiovascular disease.

It was calculated by looking at the BMI of 577,343 middle-aged people in the UK and Europe whose BMI was measured before they were followed for almost 11 years on average to see if they developed cancer.

The findings suggest that anyone who is overweight may need to consider their cancer risk, but people with cardiovascular disease may need to be especially careful when it comes to their weight.

The study defined someone with cardiovascular disease as anyone who had a heart attack, a stroke caused by circulatory disorders, heart failure or coronary heart disease, or an irregular heartbeat.

In addition, if these people were overweight or obese and had a BMI of more than 25, they were 3.4 times more likely to develop obesity-related cancers.

This was compared to a normal weight person without cardiovascular disease.

However, this result was based on only one group of people from the British Biobank Health Study analyzed by the researchers.

A second group of people from the EPIC cancer study, which involved several European countries, including Britain, did not come to the same conclusion.

Researchers assure people that being overweight or obese, even with cardiovascular disease, is only associated with 50 additional cases of cancer per 100,000 people per year.

But while obesity-related cancers account for less than half of all cancers, they include types such as colon and breast cancer, which are very common.

As a result, it was found that being overweight or obese with cardiovascular disease increases the risk of developing some form of cancer by 68 percent, compared to people of normal weight without cardiovascular disease.

Dr Helen Croker, deputy director of research and policy at the World Cancer Research Fund, which funded the study, said: “We already know obesity is a major risk factor for cancer, but these remarkable results show that risk varies depending on demand. else.” or people also have cardiovascular disease.

“Maintaining a healthy weight may therefore have even more benefits for certain groups.”