Almost one third of the global population is now overweight or obese – about 2.2 billion children and adults – with an increasing percentage of people suffering from related health conditions, according to a new study.
In another troubling finding, the rate of childhood obesity is increasing, outpacing that of adult obesity in many countries. Children and teens who carry excess weight are more likely to carry that excess weight into adulthood, placing them at higher risk of many chronic diseases.
The findings come from a major new paper published this week in The New England Journal of Medicine.
AICR research shows that being overweight or obese increases the risk of 11 cancers, including colorectal, esophageal, and postmenopausal breast. In the US alone, AICR estimates that if all adults were a healthy weight, that could prevent approximately 133,000 cancer cases a year.
Global obesity findings
The study covers 195 countries and territories from 1980 through 2015 using data from the most recent Global Burden of Disease study (GBD). GBD authors used the evidence-grading criteria of the World Cancer Research Fund (WCRF) as part of their systematic evaluation. AICR is a member of WCRF and these criteria are used for our continuous update reports, such as the breast cancer report released last month.
Key findings for obesity include:
Heavy disease burden
Increasingly, being overweight (BMI of 25-30) links to BMI-related disease and years lost to ill health, disability or early death.
In 2015, high BMI accounted for 4 million deaths globally; nearly 40 percent occurred in individuals who were not obese. A BMI of 25 to 30 is categorized as overweight; a BMI of 30 or greater is categorized as obese.
More than two thirds of deaths related to high BMI were due to cardiovascular disease. Diabetes was the second leading cause of BMI-related deaths in 2015.
For many cancers, death remained similar or slightly increased from 1995 to 2015, possibly due in part to improved treatments, while years living with the disease increased. For example, years living with breast cancer were almost double in 2015 compared to 1995.
Rates of death from a disease were calculated on what would have been observed if everyone had been at the lowest-risk BMI.
A Problem Beyond Economics
The study has several limitations, such as using some self-reported measures and sparse data in some locations. The study also did not evaluate other measures of excess body fat that may relate to health, such as waist circumference and waist-to-hip ratio.
Yet this study used the best available evidence to draw a causal link between high BMI and disease. For many BMI related health disorders, weight loss and physical activity can help.
With the prevalence of obesity increasing globally, this indicates the problem is not simply a function of income or wealth. Changes in the food environment and food systems are probably major drivers, the study concludes.
Supported by a grant from the Bill and Melinda Gates Foundation.
Institute for Health Metrics and Evaluation, Overweight and Obesity Viz: http://www.healthdata.org/data-visualization/overweight-and-obesity-viz
The GBD 2015 Obesity Collaborators. Health Effects of Overweight and Obesity in 195 Countries over 25 Years. The New England Journal of Medicine, June 2017 DOI: 10.1056/NEJMoa1614362
Published on June 25, 2017