Harris Poll: Obesity increased, cigarette smoking decreased in every five-year period

The annual Harris Poll that has measured key health risks – smoking, seat belt use, weight and obesity – for the last 28 years, provides both good and bad news.

“Do you smoke a pipe or cigars or use chewing tobacco?”

It is bad news that obesity has increased in every five year period since we started measuring it. The good news is that the proportion of adults who are obese has not changed significantly since 2006. It is good news that the proportion of adults who smoke cigarettes declined in every five year period, however it is disappointing that the number is not significantly lower this year than it was in 2005. It is good news that most adults wear seatbelts in the front seat of cars, though it is unfortunate that there has been no significant improvement since 2005.

These are the results of a nationwide Harris Poll survey of 1,010 adults surveyed by telephone between February 16 and 21, 2010. The main findings of this new survey are:

Smoking

• 17% of adults admit to smoking cigarettes in 2010. The average for the last five years (2006-2010) is 20%. In the previous five years 2000-2004, an average of 23% smoked cigarettes.
• In addition to the 17% of adults who smoke cigarettes, an additional 4% smoke cigars or pipes, or chew tobacco.

Weight and obesity

Harris uses two different measurers of obesity. Since 1983, we have used the Metropolitan Life tables for people over 25, based on height, weight and body frame. Since 2005 we have also computed the more widely used Body Mass Index (BMI). The new survey suggests that 34% of adults over 25 (using MetLife tables) or 29% (using BMI) are obese. Using the MetLife measures (we have no long term trend for BMI) the proportion of obese adults increased from 32% for 2001-2005 to 35% for 2006-2010.

Seatbelt use

The new survey finds 87% of adults claim to always wear seatbelts when in the front seat of a car, which is not significantly different from the results of all our surveys since 2005.

However, the average for 2006-2010 at 88% is better than the average of 83% in the previous five years from 2001-2005.

A word of caution

Throughout the 28 years we have conducted this research, the survey has been conducted by telephone. Recent research suggests that there is a tendency, when talking to an interviewer, to underreport socially undesirable or embarrassing behavior and information. It is possible, therefore, that all these surveys underestimate the number of smokers and obese people and overestimate the number of people who always wear seatbelts. Having said that, it is reasonable to conclude that the trends are real.

So what?

As mentioned, this new research suggests both good and bad news. But, given the lack of statistically significant changes over the last two years either of the following are possible:

We will only learn which of these is happening in surveys to be conducted over the next few years.

Sample sizes are approximately 5,000 adults for each of the five year periods, approximately 3,000 for the first period of three years between 1983 and 1985.

Methodology

This Harris Poll^® was conducted by telephone within the United States between February 16 and 21, 2010 among 1,010 adults (aged 18 and over). Figures for age, sex, race/ethnicity, education, region, number of adults in the household, number of phone lines in the household were weighted where necessary to bring them into line with their actual proportions in the population.

All sample surveys and polls, whether or not they use probability sampling, are subject to multiple sources of error which are most often not possible to quantify or estimate, including sampling error, coverage error, error associated with nonresponse, error associated with question wording and response options, and post-survey weighting and adjustments. Therefore, Harris Interactive avoids the words “margin of error” as they are misleading. All that can be calculated are different possible sampling errors with different probabilities for pure, unweighted, random samples with 100% response rates. These are only theoretical because no published polls come close to this ideal.