The past year has seen scientific studies that have varied in their estimates of the seriousness of obesity and overweight and their impact on premature death.[1] A new opinion poll by the Harvard School of Public Health finds that most Americans have not changed their minds about the seriousness of the obesity problem and do not believe that scientific experts are overestimating the health risks of obesity. In addition, they are no less likely than a year ago to be keeping track of calories, fat content, or the amount of carbohydrates they eat.

Three-fourths of Americans rate obesity as an "extremely"(34%) or "very"(41%) serious public health problem in the United States. In addition, the majority of Americans believe that scientific experts have been portraying accurately (58%) or even underestimating (22%) the health risks of being obese. Very few Americans reported believing that the health risks were being overestimated by scientific experts (15%).

"Even after all the criticism that too much attention is being paid to obesity, Americans still see this as a very serious problem for the country," said Robert J. Blendon, Professor of Health Policy and Political Analysis at the Harvard School of Public Health.

Counting calories, carbohydrates, and fats

The poll also finds approximately the same number of Americans in 2005 as in 2004 reporting that they are keeping track of the amount of calories (32% 2005, 35% 2004), fat content (47%, 46%) and the amount of carbohydrates (36%, 36%) in their daily diet. In addition, the survey finds a small increase in the number of Americans who report that they are seriously trying to lose weight from 27% in 2004 to 32% in 2005. This includes more than half (54%) of people who consider themselves to be overweight.

Obesity and Mortality

A number of issues were raised by recent studies about obesity including whether more Americans die each year from the effects of obesity than from the effects of smoking and tobacco, and whether people who are moderately overweight are more likely to die prematurely or develop a serious chronic illness than those who are at the recommended weight. Forty-one percent of Americans reported believing that the same number of people in the US die from the effects of being seriously overweight as from the effects of smoking and tobacco. In addition, half of the public (51%) thought that someone who is moderately overweight would be more likely than someone who is the recommended weight to die prematurely. However, 73% thought that a moderately overweight person would be more likely than someone at the recommended weight to develop a chronic illness such as diabetes or high blood pressure.

"Americans are pretty certain that being moderately overweight leads to serious health problems," said Blendon, "but they are not convinced that it leads to premature death."

Trust in scientific experts

The survey finds that trust in scientific experts on the issue of obesity is mixed. Only 48% of Americans reported having a "great deal" (14%) or a "good amount" (34%) of trust in the advice scientific experts give people about how to control their weight. However, 61% of Americans said they paid a lot (13%) or a fair amount (48%) of attention to the nutritional recommendations from scientific experts about how to control their weight.

Few Americans (36%) reported that they had read or seen any news stories about the recent differences in scientific findings around whether people who are moderately overweight are no more likely to die prematurely than people who are at the recommended weight. Approximately one-half (52%) of those who read or saw any news stories about the differences in scientific findings said that these stories would make no difference in the likelihood that they would pay attention in the future to advice from scientific experts on how to control their weight; only 11% said these stories would make them less likely to pay attention.

The 2004 trend data come from an ABC News/Time poll, May 10-16, 2004.

For the complete survey and power point slides see:
hsph.harvard.edu/press/releases/blendon/Obesity
hsph.harvard.edu/press/releases/blendon/ObesityTopline

Additional information about nutrition can be found at http://www.cdc.gov and hsph.harvard.edu/nutritionsource.

Methodology

This poll was designed and analyzed by researchers at the Harvard School of Public Health. The work was supported through a grant from the CDC to provide technical assistance by monitoring the response of the general public to health threats. The project director is Robert J. Blendon of the Harvard School of Public Health. The research team also includes Catherine M. DesRoches, John M. Benson, Kathleen Weldon, and Channtal Fleischfresser of the Harvard School of Public Health and Melissa J. Herrmann of ICR/International Communications Research. Fieldwork was conducted via telephone by ICR/International Communications Research of Media (PA) between June 23 -28, 2005. The survey was conducted with a nationally representative sample of 2,033 adults age 18 and over. The margin of error for this poll was 2.2%.

Possible sources of nonsampling error include nonresponse bias, as well as question wording and ordering effects. Nonresponse in telephone surveys produces some known biases in survey-derived estimates because participation tends to vary for different subgroups of the population. To compensate for these known biases, sample data are weighted to the most recent Census data available from the Current Population Survey for gender, age, race, education, as well as number of adults and number of telephone lines in the household. Other techniques, including random-digit dialing, replicate subsamples, callbacks staggered over times of day and days of the week, and systematic respondent selection within households, are used to ensure that the sample is representative.

[1] See Flegal KM, Graubard BI, Williamson DF, Gail MH. Excess deaths associated with underweight, overweight, and obesity. JAMA. 2005; 293: 1861-1867; Gregg EW, Cheng YJ, Cadwell BL, et al. Secular trends in cardiovascular disease risk factors according to body mass index in US adults. JAMA. 2005; 293: 1868-1874; Mokdad AH, Marks JS, Stroup DR, Gerberding JL. Actual causes of death in the United States, 2000. JAMA. 2004; 291: 1238-1245.

Harvard School of Public Health is dedicated to advancing the public's health through learning, discovery, and communication. More than 300 faculty members are engaged in teaching and training the 900-plus student body in a broad spectrum of disciplines crucial to the health and well being of individuals and populations around the world. Programs and projects range from the molecular biology of AIDS vaccines to the epidemiology of cancer; from risk analysis to violence prevention; from maternal and children's health to quality of care measurement; from health care management to international health and human rights.

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