ROCHESTER, N.Y. -- Every year at about this time, the Harris Poll asks a cross-section of U.S. adults about some of their most important health risks and their healthy and unhealthy behaviors, specifically their weight, seat belt use and smoking habits.

The good news is that seat belt use in the front seats of cars continues to increase, and smoking has declined. The bad news is that obesity continues to increase dramatically and the rate of decline in smoking is relatively modest and has not changed significantly for the last 10 years, contrary to much that has been written about it.

While this year's numbers are very similar to the 2006 results, the trend -- using aggregate data for each five-year period since the early 1980s -- is more informative and more reliable.

Smoking

When Harris Interactive began asking adults about their smoking habits in 1983, 30 percent of adults said they smoked cigarettes and, on average, 29 percent said they did so in the three surveys conducted between 1983 and 1985. Cigarette smoking fell to 27 percent from 1986 to 1990, to 25 percent from 1991 to 1995, and to 24 percent from 1996 to 2000. Since then, this figure has not fallen significantly. On average, 23 percent say they smoked from 2000 to 2005 and from 2006 to 2007.

Due to the bans on smoking in many offices and public spaces such as airports, restaurants and buses, smoking is much less visible than it used to be. However, the important news is not that smoking has declined, but how slow that decline has been. Other research has found that many young people still start to smoke in their teens and once they are hooked, it is extremely hard to break the habit.

Furthermore, the 23 percent of adults who smoke cigarettes understate the use of all tobacco products. In our latest survey, fully 28 percent of adults say they smoke cigarettes, pipes or cigars, or use chewing tobacco.

Obesity

Much has been written about the obesity epidemic. One of the most widely- reported comments in any Harris Poll, first made in 1994, was that "Americans are the fattest people on earth and are getting fatter every year." This is probably still true, even though many other affluent countries are also seeing very rapid increases in obesity, as they eat more and exercise less.

When these questions were first asked, the Body Mass Index (BMI) was not used and the most common measures of being overweight and obese were the Metropolitan Life tables, which are based on height, weight and body frame for adults ages 25 and older. In order to look at the long-term trends, Harris continues to use these measures.

From 1983 to 1985, on average, the Harris Poll reported that 59 percent of adults aged 25 and over were overweight. The average for 2006 to 2007 is 81 percent who are overweight. From 1983 to 1985 the Harris Poll reported 15 percent were obese, which is defined as 20 percent or more overweight. The average for 2006 to 2007 is 37 percent who are obese. This is not just an increase of 22 percentage points; it is an increase of 147 percent. Over 80 million adult Americans are now obese. And there is no reason to believe that this number will not continue to increase.

Seat Belt use

The increase in seat belt use since the 1980s is an equally dramatic trend, but of course, a very positive one. In 1983, our first survey in this series found that only 19 percent of adults claimed that they always wore seat belts when in the front seat of a car. Now, the average for 2006 to 2007 is 86 percent.

It is a safe assumption that this huge increase in seat belt use has saved many thousands of lives and serious injuries. However, other research has shown that seat belt use is higher in some other countries. Furthermore, many other countries mandate seat belt use in all seats; not, as in most states in this country, in front seats only.