Excess body weight accounted for about 3.9% of all cancers worldwide in 2012, according to a report appearing online in CA: A Cancer Journal for Clinicians, which is a peer-reviewed journal of the American Cancer Society.
The report was co-authored by investigators at the American Cancer Society; the Imperial College London and the Harvard T.H. Chan School of Public Health.
The review studied global and regional patterns in excess body weight. It also looked at factors driving the obesity epidemic; the evidence linking excess body weight to cancer risk, and policy actions that might help address the issue.
The report noted that policies, economic systems, and marketing practices that promote the consumption of energy-dense, nutrient-poor food are driving a worldwide rise in excess body weight. Making this situation far worse are changing behavioral patterns wherein high total energy intake combines with insufficient physical activity.
Doctors have long recognized that the pervasiveness of excess body weight has been increasing worldwide since the 1970s. In 2016, about 40% of adults and 18% of children (ages 5-19 years) had excess body weight.
This came to a total of 2 billion adults and 340 million children around the globe.
Unfortunately, the report discovered the prevalence of excess body weight has increased rapidly in most countries across all population groups. Some of the highest increases are in low- and middle-income countries.
Researchers said this surprising outcome is probably the result of the spread of the "Western lifestyle," that focuses on people consuming energy-dense (or sweet foods); nutrient-poor foods (such as junk food) alongside reduced physical activity levels.
An estimated 4 million deaths were attributable to excess body weight in 2015.
The worldwide cost of illnesses related to excess body weight is estimated at $2.0 trillion. The medical picture is grimmer still.
The report found out that excess body weight accounted for some 544,300 cancers -- or 3.9% of all cancers worldwide. The proportion varied from less than 1% in low-income countries to 7% or 8% in some high-income Western countries and in Middle Eastern and Northern African countries.
Being overweight and obese have been linked to an increased risk of 13 cancers.
These are cancers of the breast (postmenopausal); kidney; liver; stomach (cardia); colon and rectum (colorectal); corpus uteri; esophagus (adenocarcinoma); gallbladder; ovary; pancreas and thyroid, as well as meningioma and multiple myeloma.
Overweight is now labeled a probable cause of advanced prostate cancer, as well as cancers of the mouth, pharynx, and larynx.
