Obesity and extreme obesity may reduce life expectancy by up to 8 years and may rob adults of as many as 19 years of healthy life due to development of type 2 diabetes and cardiovascular disease (CVD), according to new data published in The Lancet Diabetes & Endocrinology.

“Our computer modeling study shows that obesity is associated with an increased risk of developing cardiovascular disease (including heart disease and stroke) and diabetes that will, on average, dramatically reduce an individual’s life expectancy and the healthy life-years free from living with these chronic illnesses compared with people of normal weight,” Steven A. Grover, MD, lead author and professor of medicine at McGill University and clinical epidemiologist at the Research Institute of the McGill University Health Centre in Montreal, said in a press release.

Grover and colleagues evaluated data on 3,992 white participants with available complete risk factor data and fasting glucose concentrations in the U.S. National Health and Nutrition Examination Survey (NHANES) 2003-2010.

For the study, the contribution of overweight and obesity to years of life lost and healthy years of life lost in adults aged 20 to 79 years were compared with those lost in normal-weight adults.

Results revealed a positive association between excess body weight and risk factors for CVD and type 2 diabetes. The effect of excess weight on years of life lost was most prominent for younger adults and decreased with increasing age, the researchers found.

For obese men (BMI ranging from 30 to 34), years of life lost ranged from 0.8 years (95% CI, 0.2-1.4) for those aged 60 to 79 years to 5.9 years (95% CI, 4.4-7.4) for those aged 20 to 39 years.

For very obese men (BMI of 35 or higher), years of life lost ranged from 0.9 (95% CI, 0-1.8) in the older age group to 8.4 years (95% CI, 7.0-9.8) in the younger age group.

For overweight men (BMI ranging from 25 to 29), however, losses were smaller and sometimes negligible.

Likewise, for very obese women, years of life lost ranged from 0.9 years (95% CI, 0.1-1.7) in those aged 60 to 79 years to 6.1 years (95% CI, 4.6-7.6) for those aged 20 to 39 years.

The researchers also found that years of healthy life, defined as years free of obesity-associated CVD and diabetes, were to two to four times greater than total years of life lost across all age groups and body weight categories.

The greatest losses were observed in adults aged 20 to 29 years, reaching about 19 years for very obese men and women, according to the data.

“These clinically meaningful calculations should prove useful for obese individuals and health professionals to better appreciate the scale of the problem and the substantial benefits of a healthier lifestyle, including changes to diet and regular physical activity,” Dr. Grover said.

In a linked comment, Edward Gregg, MD, chief of the Epidemiology and Statistics Branch in the Division of Diabetes Translation at the CDC, noted that more data are needed to inform decision-making among health care providers as well as policymakers.

“Meaningful metrics are needed for education, counseling, and health promotion. Some aspects of the clinical use of such estimates warrant further examination, and the ability of composite measures to differentiate the effect of small differences in thresholds of obesity levels is unclear,” Dr. Gregg wrote.

“This … might place a higher premium on decision-making methods that can simultaneously take a lifecourse perspective, incorporate interventions, and consider individual differences so that clinicians and public health leaders alike can effectively tackle the next phases of the obesity and diabetes epidemics.”

Reference

  1. Grover SA et al. Lancet Diabetes Endocrinol. 2014;doi:10.1016/S2213-8587(14)70229-3.
  2. Gregg E. Lancet Diabetes Endocrinol. 2014;doi:10.1016/S2213-8587(14)70242-6.