CHICAGO — Americans think they are healthier than they actually are, according to market research company Mintel.

Seven in ten respondents to a survey told Mintel they think they are in good or excellent health, but the Deloitte Center for Health Solutions’ Connected Care says 100 million Americans suffer from chronic illnesses such as heart disease, diabetes or hypertension.

Americans seem in denial about their weight problems a well. Only 25% of those who responded to the survey said they were obese or overweight, but the Centers for Disease Control and Prevention, Atlanta, has reported 67% of Americans are either overweight or obese. To back this up, Mintel also calculated the body mass index of respondents in a separate report and found 65% of those in the research effort were overweight or obese.

"The challenge clearly lies in getting Americans to accept and admit that their health isn’t optimal," said Krista Faron, senior analyst at Mintel. "Right now we say one thing, but then our actions contradict those perceptions and best intentions. All companies from health care to food need to get adults who are at risk or ill to recognize their issues, accept responsibility and make lifestyle changes."

In addition, 70% of adults think they should exercise more. Less than 37% said they exercise regularly and about half work out twice a week or less. About two-thirds of respondents said they try to eat healthier foods, but 59% said they eat the foods they like regardless of the calories.

"People have lofty, admirable goals of eating healthier, exercising more and treating their bodies better," Ms. Faron said. "Our research suggest that implementation of these goals is challenging. Many people need help and guidance to understand where their health is lacking and how they can improve it."