Three habits are key to weight loss and sustained weight control, a new study finds.
Women in the study who were most successful at losing weight kept track of their food intake in a journal, didn't skip meals and avoided eating out, especially for lunch.
"Our study was unique in that it looked at a large array of weight-loss behaviors to see what worked and what didn't," said study researcher Dr. Anne McTiernan, of the Fred Hutchinson Cancer Research Center in Seattle. "We were surprised at how much of a difference using food journals and eating at home made," McTiernan said.
Among the women in the study, who were between ages 50 and 75, those who cultivated each of these habits lost five to eight pounds more than women who didn't engage in these practices.
"This study highlights the important strategies for maintaining weight loss over time, including self-monitoring through [food diaries], regular eating patterns and a healthy food environment [by minimizing eating out)," said Dr. Anne N. Thorndike, of Harvard Medical School, who was not involved in the study.
Thorndike said she was not surprised by the three habits that led to the greatest success. "These findings really mirror what I see in clinical practice," she said.
Three simple rules?
McTiernan and colleagues tracked the habits of 123 women who were taking were part in the larger Nutrition and Exercise for Women study. At the study's start, the participants' average age was 58, and their average body mass index (BMI) was 31.3. (People with BMIs of 30 and higher are considered obese.) During the year-long study, the participants lost, on average, 10.7 percent of their body weight.
The researchers found that women who kept diligent food logs lost about six more pounds than those who did not keep a food diary.
"We found that the better women in our study were at consistently writing down everything they ate and drank, the more weight they were able to lose," McTiernan said.
The study also found that women who consistently ate three meals daily lost almost eight more pounds, compared with those who reported skipping meals. People who skip meals are likely to be hungrier by the next meal, and overeat, the researchers said.
Eating meals in restaurant may result in a lack of control over calorie intake. Women who ate lunch outside their home at least once a week lost five fewer pounds on average, compared with those who ate out less often. The more meals out that women ate, particularly lunches, the less weight the women lost.
And fast food can't be blamed, according to the study, because only 10 percent of participants reported frequenting fast-food restaurants.
"I think the real key is knowing how many calories you're getting, and controlling the amount," McTiernan said. That's very difficult to do in restaurants where you can't always tell how many calories are in your meal, she said.
The approach taken in the study allowed the researchers to identify the behaviors associated with long-term success, said James O. Hill, professor at the University of Colorado, and director of the Colorado Nutrition Obesity Research Center, who was not involved in the research.
Both Hill and Thorndike said that the results are likely not limited to overweight postmenopausal women, but also apply to the general population.
Are total calories more important than calorie type?
Studies, including this one, consistently show that focusing on restricting the total number of calories consumed yields better weight-loss results than following any diet based on food types, such as low-fat or low-carbohydrate diets.
But a study published in June in the Journal of the American Medical Association shook up this notion, suggesting a low-carb diet results in more efficient weight loss, compared with a low-fat diet.
McTiernan, however, noted that in that study, participants remained on a certain diet for only one month. She emphasized that most research still points to the golden rule of "calorie reduction is the key."
Thorndike agreed. "Current literature strongly supports reducing total calories as the most important intervention for weight loss."
Ultimately, McTiernan said she believes each person needs to find a system of calorie reduction that works best for him or her.
The experts also said that exercise is an important part of any long-term plan to stave off weight gain.
"I believe the most important part of a plan to keep weight off is incorporating regular physical activity into your life," Hill said.
The new study is published July 13 in the Journal of the Academy of Nutrition and Dietetics.