Obesity Grows Despite Diets to Curb It

Panelists warn of future heart disease

FRIDAY, March 5, 2004 (HealthDayNews) -- Americans are getting morbidly fatter even as they speed up their efforts to lose weight.

The American Heart Association hosted a panel Friday to try to unearth what Americans eat and what, exactly, is contributing to the rising tide of obesity.

Spurred by the aggressive marketing of diets that promote fat over carbohydrates, researchers at the Mayo Clinic decided to see if these campaigns were affecting what people were eating. After surveying 1,200 residents of Olmstead County, Minn., the answer was a resounding yes. Between 1999 and 2003, a larger proportion of calories were coming from fat, saturated fat, and dietary cholesterol.

"The findings reverse some of the trends seen over the past 20 years," says lead author Dr. Randal J. Thomas. Thomas adds that these findings "suggest that there are some tough times ahead with respect to heart disease."

While the popularity of low-carb, high-fat diets may indeed be behind some of these changes, Thomas says many other factors could also be contributing.

Another study found a number of characteristics that seemed to be related to consuming larger portion sizes among a group of postmenopausal women with type 2 diabetes who were trying to follow the Mediterranean diet. This group has a high risk of developing coronary heart disease.

Women with higher incomes, education levels, and body weight and a lower age (within the range, which began at 45) tended to eat larger sizes. Also, larger portion sizes were linked to lower levels of physical activity, higher "bad" cholesterol, less ability to manage stress, greater depression, and higher blood pressure.

Researcher Kristie J. Lancaster of New York University found important differences between ethnic subgroups of African-Americans who are usually lumped together in terms of risk. Non-Hispanic blacks who were born in the United States had a higher 10-year risk of developing coronary heart disease (CHD) than those born outside the United States. Those born in the United States also had a higher proportion of calories from fat and saturated fat and ate fewer fruits, vegetables and legumes. They were also more likely to smoke.

"All black groups need to improve in diet and CHD risk," Lancaster says, "but, in particular, African-Americans have greater needs when it comes to diet and CHD risk, so we need more investigation of these groups."

A national survey of 6,739 adults found that about half felt that "dinner was not right without meat." Meat, of course, tends to have more fat, and people who consume more meat tend to be heavier. Less than a third of the respondents (29 percent) felt they ate enough fruit and vegetables according to the government's recommended guidelines.

"This information could be used in the development of nutritional information for healthy eating," says Alison Jane Rigby of Stanford University.

Finally, another study looked at 4,000 participants in four countries -- China, Japan, the United Kingdom and the United States -- to find associations between weight and dietary intake.

"We looked at people who were winning the game of weight control," says Linda Van Horn of Northwestern University. "Lo and behold, what we did find is that, without exception, a high complex-carbohydrate, high-fiber, high-vegetable diet was associated with a low body mass index."

High protein, especially high animal protein, diets were associated with a greater body mass index. "The association between dietary patterns that are associated with lower body weight are consistent with those the American Heart Association has recommended for years," Van Horn says.

The overall weight loss message, as AHA spokesman Dr. Robert H. Eckel put it, is "very, very simple but difficult to implement."

That message is: take in less than you give out. "It has to be a matter of energy balance," Van Horn says. "[In our study], the healthiest people were eating the most calories but had the leanest body mass index, but the point is to be physically active. That allows you the discretion to have additional calories. You can get away with more calories as long as you're burning them off."

One way to do that, Thomas says, is to "turn off the TV and eat at home. Doing simple things like that can help you be more active."

And Americans need to get away from this bipolar debate on carbohydrates vs. protein, Eckel says. "When we're talking about weight, it's no longer fat or carbohydrate or protein. It's pure calories," he says. "We need to turn the public's attention to calories again."

More information

The American Heart Association has more on diet and nutrition and on exercise and fitness.

SOURCES: News teleconference, March 5, 2004, with Robert H. Eckel, M.D., American Heart Association and University of Colorado Health Sciences Center; Randal J. Thomas, M.D., Mayo Clinic; Deborah J. Toobert, Ph.D., Oregon Research Institute; Kristie J. Lancaster, Ph.D., R.D., New York University; Alison Jane Rigby, Ph.D., M.P.H., R.D., Stanford University; Linda Van Horn, Ph.D., Northwestern University; conference abstracts
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