U.S. adults may be more aware of the need to exercise and count calories than they once were, but more of them than ever are overweight.
The number of overweight adults, which had remained stable at about a fourth of the adult population from 1960 through 1980, suddenly jumped to a third of all adults between 1980 and 1991, according to a recent study by the National Center for Health Statistics in the Centers for Disease Control and Prevention in Atlanta.
For purposes of the study, obesity was defined as being 20 percent or more above a person's desirable weight. That is about 25 pounds for an average 5-feet-4-inch woman and 30 pounds for an average 5-feet-10-inch man.
The increase in obesity rates continues despite a growing awareness that it has a negative effect on health and despite the continued growth of the diet industry, now estimated to have revenues of $40 billion to $50 billion a year.
The study's figures on children were not available last week, but several experts who had seen the data said that obesity among the nation's youth was increasing at an even faster rate than it was among adults.
Although the study confirms what experts have said they suspected, it is the first time the growth of the problem in the '80s has been measured.
The data on American weight patterns have been collected in several government surveys that began in 1960. The studies are designed to
determine the relationship between diet and health and help the government implement its food assistance programs.
The latest study found that the groups with the highest proportion of overweight people were black non-Hispanic women, at 49.5 percent, and Mexican-American women, at 47.9 percent. Those levels represent increases of 12.2 percent and 15.7 percent, respectively, compared with the 1980 rates.
Although the percentage of white non-Hispanic women who are overweight is lower, 32.4 percent, obesity in that group increased at a much higher rate, 35.6 percent, from 1980 to 1991.
The study offers additional support to health and nutrition professionals who argue that a national campaign to reduce obesity is essential to contain health care costs.
Dr. Philip Lee, assistant secretary of health in the Department of Health and Human Services, said Friday: "The government is not doing enough. It is not focused. We don't have a coherent across-the-board policy. We are in the process of developing one."
On Tuesday, the Journal of the American Medical Association will publish an article based on the study's findings about adults. In an editorial that will accompany the article, Dr. F. Xavier Pi-Sunyer, director of the division of endocrinology, diabetes and nutrition at St. Luke's-Roosevelt Hospital and a professor of medicine at Columbia University, wrote: "The proportion of the population that is obese is incredible. If this was about tuberculosis, it would be called an epidemic."
Dr. Pi-Sunyer added: "The problem with obesity is that once you have it, it is very difficult to treat. What you want to do is prevent it."
Despite the relationship between obesity and chronic diseases of the heart and other organs, obesity is usually defined not as a disease, but as a condition that will yield to old-fashioned willpower.
Neither the federal government, insurance companies nor the medical profession devote many resources to preventing obesity. According to the Agriculture Department, the food industry spends $36 billion a year on advertising in the United States.
But federal expenditures for nutrition education are minuscule. For example, the government allots states $50,000 each for nutrition education in schools. The annual advertising budget for Kellogg's Frosted Flakes is twice the budget for the National Cancer Institute's entire "5 a Day" program, which promotes the consumption of fruits and vegetables.
Obesity cost the nation $68.8 billion in 1990, according to a study by Graham Colditz, an associate professor of medicine at Harvard Medical School. His study, which appeared in PharmacoEconomics, an international journal of economic and quality evaluation of drug therapy, drew its estimates from the costs of medical problems that have been tied to obesity, including cancer, cardiovascular disease, adult-onset diabetes and gallbladder disease.
Few insurance companies or health maintenance organizations will reimburse the cost of medical or nutritional counseling to lose weight. Among the health care bills now being considered by Congress, preventive nutrition programs and reimbursement for nutrition counseling are either optional or absent.
"There is no commitment to obesity as a public health problem," said Dr. William Dietz, director of clinical nutrition at the New England Medical Center in Boston. "We've ignored it and blamed it on gluttony and sloth."
Experts agree that the root causes of obesity in this country -- a sedentary lifestyle and an abundance of food -- are very difficult to change.
"It's what I call the 3,700-calorie-a-day problem," said Marion Nestle, chairwoman of the Department of Nutrition at New York University and managing editor of the 1988 Surgeon General's Report on Nutrition and Health.
The Department of Agriculture reports that the American food supply produces 3,700 calories a day for every man, woman and child. Women's caloric needs are only about half that amount, and men's about two-thirds.
But people are constantly bombarded with food messages that encourage them to eat far more than they need, Ms. Nestle said.