More Americans are happy with their weight, a new poll suggests.

In a recent Gallup poll, 49 percent of Americans said they would like to lose weight -- the first time in at least 25 years that less than half of Americans reported wanting to lose weight, according to the poll. The number is down from a high of 62 percent who said in 2004 that they wanted to lose weight.

The poll also found that 41 percent of Americans said that they would like to stay at their present weight, according to the poll. [The Best Way to Lose Weight Safely]

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Similarly, 56 percent of Americans consider their weight to be "about right," whereas 37 percent said they consider themselves to be "very" or "somewhat overweight," according to the poll, which was conducted from Nov. 4 to Nov. 8.

But obesity rates are still on the rise in America.

In fact, the rising percentages of people who are overweight and obese may partly explain why so many Americans consider themselves to be at a normal weight, said Dr. Holly Lofton, the director of the Medical Weight Management Program at New York University Langone Medical Center.

Two-thirds of Americans are overweight or obese, putting people who are in the "normal" weight range in the minority, Lofton told Live Science. (A "normal" weight range means the individual has a BMI that's between 18.5 and 24.9.)

"If everybody looks like their friends, then you think that you're just normal weight," Lofton said. "But you're normal weight by American standards, not by medical standards," she said.

The poll results seem to be in line with this statement -- Gallup noted that the vast majority of people in the poll who did say they were overweight also said they would like to lose weight, which "suggests that the decline in the percentage of Americans wanting to lose weight is more attributable to fewer people saying they are overweight, than to overweight people being less likely to say they want to lose weight," according to the Gallup poll, which was posted online on Nov. 27.

Shifting standards of beauty -- particularly female beauty -- may also have contributed to the change.

Girls don't want to look like waif-like models anymore, and that's certainly a good thing for confidence and body image, Lofton said. But people still need to focus more on their health, even if they are less focused on their BMI, she said.

"You can be in the normal BMI range and still have prediabetes," Lofton said. Likewise, a person can fall in the overweight range and be metabolically healthy, she said.

Indeed, the most recent weight-management guidelines from the American Heart Association and other professional organizations advise that people who are overweight -- but who do not have any additional risk factors for heart disease -- should try and maintain their weight, rather than lose weight.

Motivation gap?

And although 49 percent of Americans reported that they "would like to lose weight," only 24 percent reported that they were "seriously trying to lose weight," according to the poll.

Some people may simply say they want to lose weight because we're exposed to an overwhelming amount of information about weight loss every day, Lofton said.

But as to why only half of those people say they are seriously trying, Lofton noted that the poll only represents one small slice of time.

If you asked the same question at a different time of year, you would probably get the same percentage, but with different people, she said.

You'll have a person who is dieting in the beginning of the year, and not dieting a few months later, she said. Then, a person who didn't diet in the beginning of the year goes on a diet, she said.

Some of this switching on and off diets is likely because dieters often go to extremes, and choose diets that are unsustainable, she said.

For people who want help in taking the first steps toward healthy weight loss, medical providers can be very useful, Lofton said.

A doctor can look over your medications to see if any are contributing to weight loss, or give some simple exercise recommendations, she said. You don't need to go right to a specialist for weight loss, she said.

Follow Sara G. Miller on Twitter @SaraGMiller. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.