BMI and Increased Death Rates: Hazards Comparable to Smoking

On March 18, 2009, The Lancet posted on its website a prepublication of a worldwide collaborative analysis of body mass index (BMI) and increased death rates among 900,000 adults in 57 prospective studies. Florida Atlantic University researcher Charles H. Hennekens, M.D., the first Sir Richard Doll Research Professor in the Charles E. Schmidt College of Biomedical Science, served as a major investigator in two of the large scale studies, and enrolled and followed approximately 144,000 adults.

The analyses were led by the Clinical Trial Service Unit at the University of Oxford in the United Kingdom where Sir Richard Doll was the Regius Professor of Medicine and Hennekens is a Visiting Fellow. Hennekens was the founding principal investigator of the Physician’s Health Study composed of approximately 22,000 physicians, and the cardiovascular component of the Nurses Health Study composed of approximately 122,000 nurses.

BMI, a ratio of weight to height (weight in kilograms divided by height in meters squared), was a strong predictor of death both above and below the apparent optimum of about 22.5-25. The progressive excess in mortality above this range is due mainly to vascular diseases. Median survival (loss of life) is reduced by two to four years at ages 30-35 and eight to ten years at ages 40-45, which is comparable to the hazard of cigarettes.

“I am deeply concerned that the United States is the fattest society in the world and likely to be the fattest in the history of the world,” said Hennekens. “Unfortunately, most people prefer prescription of pills to proscription of harmful lifestyles. I am, however, optimistic that weight loss of five percent or more combined with a brisk walk for 20 or more minutes daily will significantly reduce cardiovascular and total deaths.”

According to the U.S. National Institutes of Health, approximately two-thirds of adults age 20 or older are overweight or obese with BMIs greater than 25, and nearly one-third have BMIs greater than 30. Less than one-third are at a healthy weight with a BMI of 18.5 to 24.9. In 1995, the economic cost of overweight and obesity in the U.S. alone was estimated to be $117 billion. According to the U.S. National Center for Health Statistics, 40% of adults age 40 or over have metabolic syndrome, a constellation of obesity leading to abnormal lipids, high blood pressure and insulin resistance, a precursor of diabetes, which continue to increase at alarming rates.

Hennekens cautions that “unless Americans lose weight and increase their levels of physical activity, cardiovascular disease will remain the leading killer in the U.S.” He adds, “The export of our diet and lifestyle, together with tobacco, to developing countries will result in cardiovascular disease emerging as the leading killer in the world.”

- FAU -

Florida Atlantic University opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 26,000 undergraduate and graduate students on seven campuses strategically located along 150 miles of Florida's southeastern coastline. Building on its rich tradition as a teaching university, with a world-class faculty, FAU hosts ten colleges: College of Architecture, Urban & Public Affairs, Dorothy F. Schmidt College of Arts & Letters, the Charles E. Schmidt College of Biomedical Science, the Barry Kaye College of Business, the College of Education, the College of Engineering & Computer Science, the Harriet L. Wilkes Honors College, the Graduate College, the Christine E. Lynn College of Nursing and the Charles E. Schmidt College of Science.