Fewer people say they're on a diet

• One possible contributor: In 2012, only 23% said people at a normal weight are more attractive
• January is a hot time for dieting, right after the holidays, which is the lowest point of the year
• Analyst says people may be more accepting of their weight because losing it is so hard

Dieting is down but not out.

On average, about 20% of people said they were on a diet during any given week in 2012, down from a high of 31% in 1991, according to new data from the NPD Group, a market research firm.

Women showed the biggest decline, with 23% reporting being on a diet in 2012, vs. 36% in 1991.

That drop may partially explain this finding: About 23% of people in 2012 said that those who are not overweight look a lot more attractive, down from 55% who thought that in 1985.

People may be more accepting of their weight because that's easier than trying to exercise and eat less, says Harry Balzer, NPD's chief industry analyst.

"It sounds like some people have thrown in the towel, and I can see why, because dieting is difficult," says Elizabeth Ward, a registered dietitian in Boston and author of MyPlate for Moms: How to Feed Yourself and Your Family Better. "If people would just adopt a few changes in their exercise habits and eating habits, they wouldn't have to go on a restrictive eating plan ever again."

For the NPD data, respondents could define "diet" any way they wanted. By far the most popular diet is one that people say "they made up, one they call 'my own diet,'" Balzer says. About a third of people follow a plan of their own, he says.

Dieting has negative connotations, so it's possible that people were trying to lose weight but didn't call it a diet, he says.

In fact, another recent study, from the International Food Information Council Foundation, showed that about 55% of people are trying to drop some weight.

The NPD research shows that "the desire to lose weight is much greater than the percentage of people who are on a diet," Balzer says, adding that almost 60% of adults want to lose at least 20 pounds.

About two-thirds of people in the USA are overweight or obese, according to government data.

Other findings from NPD:

-- About 22% of people are on a diet right now. "This is a tradition at this time of year," Balzer says. "It's always about this same percentage of people."

-- During the holidays in 2012, about 15% of adults were on a diet. That used to be about 18% or 19%, he says. The holidays are the lowest dieting point of the year, he says. "People start off with good intentions (in January) but lose interest before the end of the year."

-- In 2012, 26% of all dieters said they followed a diet for less than a month; 36% for one to six months; 11% for seven to 12 months; 27% for more than a year.

-- 9% of all dieters have been on a diet for more than five years.