If the results of a new survey in the U.S. on obesity are to be believed, most obese Americans are eating a healthy diet and are doing some form of vigorous exercise three times a week or more.

As many as two-thirds of Americans are overweight or heavier, and nearly one-third qualify as obese, according to the U.S. Centers for Disease Control and Prevention.

Respondents to the survey were contacted through computer random digit dialing in a period from January to March and the researchers relied on the respondents to be truthful about their height, weight and other answers.

The survey of 11,000 people conducted by Thomson Medstat, a health-care research firm, has left the researchers wondering if America’s fatties have any understanding of the meaning of a healthy diet and regular, vigorous physical activity.

Apparently over three-quarters of obese Americans claim to have healthy diets and almost half say they do vigorous exercise three times a week or more.

When it came to snacking habits, 28% of obese people said they snack two or more times a day, compared to 24% of people of normal weight.

However the survey omitted one essential question-how much do you eat?

Of the 11,000 surveyed 3,000 were obese or morbidly obese, 4,200 others were overweight, 3,800 were of normal weight, 200 were underweight.

Dr. David Schutt, the company’s associate medical director says they were surprised how some responses from obese and overweight people paralleled those of thinner respondents, and if what the respondents said was really the truth, the lifestyles of obese and people or normal weight do not seem to be all that different.

Around 19% of obese people said they always read nutritional labels on food packages, compared with 24% of normal-weight people, and about 29% of obese people said they eat out at restaurants three or more times a week, compared with 25% of normal-weight people.

However one telltale difference was the answer to the question: How often do you eat all of the food you are served at restaurants? About 41% of obese people said they always did, while 31% of normal weight people always did.

The data about eating and exercise are part of a larger package of survey information being marketed to employers, hospitals and other customers and will not be published in a peer-reviewed scientific journal.

Centers for Disease Control and Prevention