Are you eating yourself to an early grave?

By Kate Bass, B.Sc.Dec 5 2014

A new study, published today in The Lancet Diabetes & Endocrinology, has shown that obesity may shorten life expectancy by ≤8 years and reduce the duration of healthy life by ≤19 years as a consequence of developing diabetes and/or cardiovascular disease.

Despite the known link between being overweight and life-threatening complications such as diabetes and cardiovascular disease, more than two-thirds of US adults are still overweight or obese.

The study analysed data from the US National Health and Nutrition Examination Survey (NHANES, 2003–2010) to assess the risk of developing diabetes and cardiovascular disease in adults (20–79 years old) of different body weights. The results were then compared with data for people of normal weight impact to estimate the impact of being overweight or obesity on the duration of life and healthy life.

The study showed that, compared to normal weight, obesity is associated with an increased risk of developing cardiovascular disease (including heart disease and stroke) and diabetes, which in turn can shorten life expectancy and the number of years of life free from these chronic illnesses.

Being overweight (BMI 25–<30 kg/m²) reduced life expectancy by ≤3 years and the effect increased with increasing weight; obese individuals (30–<35 kg/m²) lost 1–6 years, and the very obese (≥35 kg/m²) lost 1–8 years of life. The impact of excess weight on life expectancy reduced with increasing age.

Furthermore, in addition to the reduction in life expectancy, obesity was shown to shorten the duration of healthy life (years without obesity-associated cardiovascular disease and diabetes). Being overweight or obese was associated with the loss of two to four times as many healthy life-years as total years of life lost. The decrease in healthy life-years was most pronounced in young adults (20–29 years old), amounting to around 19 years for very obese men and women.

Dr Steven Grover, Professor of Medicine at McGill University explained

The more an individual weighs and the younger their age, the greater the effect on their health, as they have many years ahead of them during which the increased health risks associated with obesity can negatively impact their lives...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.

It is hoped that the development of such meaningful metrics will facilitate education, counselling, and health promotion allowing clinicians and public health leaders to effectively reduce the scale of obesity and diabetes.