FRIDAY, July 13 (HealthDay News) -- If you are trying to lose weight, adopting three key strategies will boost your chances of success, new research suggests.

Keep a food journal, avoid eating out often and don't skip meals.

"Greater food-journal use predicted better weight-loss outcomes, whereas skipping meals and eating out more frequently were associated with less weight loss," writes Dr. Anne McTiernan, a research professor of epidemiology at the University of Washington and the Fred Hutchinson Cancer Research Center, Seattle. In the new study, she and her colleagues looked at a wide range of behaviors and meal patterns to evaluate what works and what doesn't.

Their findings are published July 13 in the Journal of the Academy of Nutrition and Dietetics.

The study lends support to the value of many strategies long suggested for weight loss or maintaining a weight loss, McTiernan said. "Our study was unique in asking about all of these behaviors in one weight-loss intervention study, to see which ones actually worked."

McTiernan evaluated changes in body weight in 123 postmenopausal women, aged 50 to 75, who were overweight or obese, over a year. The women were in a diet-only group -- reducing calories to lose weight -- or a diet-plus-exercise group.

Their average body mass index (BMI) was 31.3 at the study start. BMI is a measurement of body fat that takes height and weight into account; a BMI of 30 or higher is considered obese.

The women completed questionnaires about what they ate, their meal patterns and behaviors such as eating out and keeping food diaries or journals.

After a year, women in both groups lost an average of 11 percent of their start weight, meeting the goal of the study. On average, the women lost 19 pounds.

However, McTiernan noticed some strategies produced more weight loss.

Women who kept food journals -- writing down everything they ate -- lost about 6 pounds more than those who did not keep them.

Women who skipped meals lost about 8 fewer pounds than those who had more regular meal patterns.

Eating out often was linked with less weight loss. While overall restaurant eating was linked with less weight loss, the strongest link was with lunch out. Those who ate out for lunch at least once a week lost about 5 fewer pounds less than those who ate out less frequently.

If used consistently, McTiernan said, the food journal makes you accountable. In keeping a journal, it's important, she said, to record everything -- toppings, sauces, condiments. Portions should be measured so you're writing the correct amounts, she said. With today's technology, it's easy to keep a food diary at hand. It can also be low-tech -- a simple pad of paper, she said.

"The best food journal is the one you'll actually use," she said.

Eating out is linked with less weight loss because it's difficult to compute the calories, added fats and sugars in a restaurant meal, even with nutrition guides, she said.

"We didn't test men, but there would be no harm in men trying these methods also," McTiernan said.

Dr. Michael Aziz, an internist at Lenox Hill Hospital, in New York City, said the study findings add support to what experts have said about weight loss for years.

The food journal is a good idea not only to count calories but to look at the overall health quality of your diet, he said.

Skipping meals once in a while may be understandable, but not as a habit, he said. "Over time, skipping meals habitually could make your metabolism slower, affecting [the hormone] leptin and thyroid hormones," he said.

Eating out makes it difficult to stick to a plan, he said. "Once you eat outside, you have no control over portions," he said. "You don't know how your food is prepared."

Another expert, Connie Diekman, director of university nutrition at Washington University in St. Louis, said the study ''provides more support to the fact that developing awareness of what and how much we eat is key to achieving, and maintaining, weight loss.''

While food diaries may seem difficult to some to keep up, the study shows that it can produce more weight loss, Diekman said.

One limitation of the study, also pointed out by the researchers, is that the women were mainly white, so the findings may not apply to others. However, much other research has found a link between food journals or diaries and weight loss, Diekman said.

More information

To learn more about keeping a food diary, visit the U.S. National Heart, Lung, and Blood Institute.

Copyright © 2012 HealthDay. All rights reserved.