National Guidelines for Ideal Weight may be too Restrictive for the Elderly, Yale Researchers Find

Little evidence exists to support the idea that older people who are moderately overweight have a higher risk of illness or death, Yale researchers report in a study published in today’s issue of the Archives of Internal Medicine.

“Based on our results, physicians and policy makers should consider the patient’s age in making recommendations about weight loss and, for older patients, focus their attention on people who are in obese and near-obese weight ranges,” said Harlan M. Krumholz, M.D., associate professor of internal medicine and cardiology at Yale School of Medicine and the study’s senior author.

National guidelines have indicated that overweight and obesity are major risk factors for illness and death. Overweight is defined as a body mass index (BMI) of 25 to 29.9 kg/m2 and obesity as a BMI of 30 kg/m2 or greater for all adults 18 years and older. BMI is weight in kilograms divided by the square of height in meters. A 5’7” person weighing 180 pounds would have a BMI of 28. With this definition, Krumholz said more than one-third of Americans 70 years and older are considered overweight and another one in six are considered obese.

Krumholz and his team investigated the evidence supporting these cut-offs for older people by performing a systematic review of the medical literature, mainly from the 1998 National Heart, Lung and Blood Institute’s U.S. Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults.

“We found that in general, higher weight is associated with a smaller excess risk in older people compared with younger people,” Krumholz said. “We also found little evidence that older persons who are mildly or moderately overweight (up to 27 kg/m2) have a higher risk of all-cause and cardiovascular death.”

Despite these findings, Krumholz warns that obesity and near-obesity (body mass index of 28 kg/m2 or more) is associated with an increased risk of death even among those who are 75 years and older.

Krumholz said future guidelines should consider the evidence for specific age groups when establishing standards for health weight. “Adverse reactions associated with calorie-restrictive diets in elderly persons and the potential harm of diet-induced weight reduction do not support recommendations for weight loss interventions in the elderly population,” he said.

Other researchers on the study included first author, Asefeh Heiat, M.D., of Griffin Hospital and the Department of Epidemiology and Public Health at Yale and Viola Vaccarino, M.D., who was in the Department of Epidemiology and Public Health when the study was done and is now at Emory University.