Women with a sunny disposition may also have an easier time adopting healthy habits, according to a new study.
Researchers found that women who were more optimistic were better able to follow healthy eating guidelines, both when they were instructed to do so and when they chose to make changes on their own.
The authors noted that the biggest help for making diet improvements is not necessarily optimism itself, but the skills that tend to go with it.
"It's not just having a sunny outlook - rather, this is a marker of other things people do," said Melanie Hingle, a dietician at the University of Arizona in Tucson. She led the new study, which was published in the Journal of the Academy of Nutrition and Dietetics.
"People who want to make lifestyle changes should focus on skill-based factors that can help them whether or not they are an optimist," she told Reuters Health.
The study used data collected as part of the Women's Health Initiative, a study of a national sample of postmenopausal women between the ages of 50 and 79.
The researchers analyzed data from two groups of women: more than 13,500 who had been part of a program to improve their nutrition - mainly by decreasing fat intake - and another 20,000-plus who were not asked to make any changes to their diet.
The women's optimism levels had been evaluated with a questionnaire as part of the study. Another survey aimed to evaluate the overall healthfulness of participants' diets at the beginning of the study and one year later.
Hingle and her team found that the most optimistic one third of the women saw the most improvement in their diets, whether or not they had completed the nutrition program.
On a scale measured from zero to 110, where higher numbers indicate better diet quality, women with the highest optimism in the nutrition program improved their diet by 1.8 points, and those with the lowest optimism improved their diet by 1.4 points. Among women not in the program, scores improved by 1.0 point for those with the highest initial optimism and by 0.3 points for those with the lowest. The differences were considered statistically meaningful.
The least optimistic women also started out with less-healthy diets, on average, than those who had sunnier dispositions.
Yet optimism itself is almost beside the point, Hingle said.
People who want to adopt healthier behaviors - whether quitting smoking, eating more vegetables or getting more exercise - should instead focus on the skills that tend to make optimistic people successful at those ventures, she said.
"You can't tell someone who's a pessimist to be an optimist. Instead, look at the traits that make optimists successful," Hingle said.
One such skill is self-regulation, or being aware of one's behavior as it is unfolding. In the case of healthy eating, that includes monitoring eating habits, whether by making a mental note or keeping tabs in a journal.
Self-regulation is "choosing what you are eating and making a conscious decision in that moment," Hingle said.
Another strategy to successfully adopt a new habit is finding healthy ways to cope with unpleasant emotions and stress instead of, for example, eating junk food or smoking. For junk food addicts, that means getting the unhealthy foods they tend to reach for when stressed - whether potato chips, cake or sugary soft drinks - out of the house, and channeling frustration into something more productive.
"It's about finding a different activity to occupy that moment when you're feeling stressed, such as coping with breathing exercises, talking to a friend, going for a walk or even going through some guided imagery," Hingle said.
"The goal is to help you move past that stressful moment instead of reaching for food," she said.
Optimistic people may also have better social support, whether as a cause or a result of their more-positive thinking. That's important because the support of friends and family can make it easier to get healthy.
The point, Hingle said, is that learning new skills can help anyone trying to turn over a new leaf.
"It doesn't really matter if you're an optimist or a pessimist. Either way, you can make positive changes to your diet," she said.