Many elderly Americans are at risk of illness and injury because of malnutrition caused partly by a defect in the way their body regulates food intake, a researcher reported Saturday.
The findings suggest that older people who are underweight or losing weight would benefit from heartier meals and possibly from taking nutritional supplements before meals, said Barbara Rolls, a professor of nutrition at Pennsylvania State University.
“The elderly are very health conscious, and they are choosing low-fat foods. Some of them shouldn’t be,” Rolls said in an interview at the annual meeting of the North American Association for the Study of Obesity.
Perhaps one-third of Americans over age 60 or 65 are underweight or losing weight, she said.
Rolls tested the effects of giving various kinds of before-meal snacks to a group of 16 men aged 18 to 35 and another 16 men aged 63 to 84. She then allowed them to choose their own lunches from a variety of high- and lowfat foods.
The snacks were varieties of yogurt adjusted to have different nutritional properties. Men were chosen for the study because they respond more sensitively than women to this kind of testing, Rolls said.
She found that the older men ate less than the younger men when no before-meal snacks were given.
When either high-fat or high-carbohydrate snacks were given, the young men adjusted by eating less at lunch, so their total calorie intake remained within 10 percent of what it had been when they ate lunch without a snack.
The older men, however, were unable to properly regulate their intake. When given either a high-fat or high-carbohydrate snack, the older men ate enough at lunch to push their overall calorie intake 30 percent above what it had been with no snack.
That indicated that the body’s mechanism for regulating food intake had gone awry in the older group. The disorder in that mechanism could be one reason why some elderly do not eat enough - their bodies are not properly signaling that they should eat more.
The findings, combined with other research, also suggest that when older people lose weight because of illness they often aren’t able to regain the weight, Rolls said.
Dr. William Dietz of the New England Medical Center in Boston, a member of a government committee that is about to release new national dietary guidelines, said Rolls’ study is consistent with other research finding disorders in food regulation among the elderly.
The federal guidelines, to be released in December, will recognize the importance of weight maintenance in some elderly people, while also acknowledging that other older people should lose weight, Dietz said.
Rolls said malnourishment in the elderly is also associated with an increased risk of chronic diseases and death.
Her study suggests that the elderly might boost their energy intake by eating a high-energy snack before meals.