People who follow a diet typical of the Mediterranean region might dodge the added pounds that often come with aging, hints a new Spanish study.

However, the researchers can't be sure if it was the diet itself or related healthy behaviors that were responsible for staving off the weight.

The Mediterranean diet is generally rich in fish, fruits, vegetables, legumes and cereals, while low in red meats and dairy. Previous research has uncovered benefits for its followers, including protection from cardiovascular disease and diabetes, as well as weight loss among those who are already overweight or obese.

Yet doubts continue to linger over the potential caloric costs of the diet's high fat content, largely in the form of olive oil, noted lead researcher Juan-Jose Beunza of the University of Navarra.

"The question we wanted to answer was: What is the effect of the Mediterranean dietary pattern among young, non-obese, healthy people? And we found it is a convenient dietary pattern since it slows down the weight gain normally observed with age," Beunza told Reuters Health in an e-mail.

Beunza and his colleagues recruited more than 10,000 Spanish university graduates, averaging 38 years old, and had them fill out a 136-item food frequency questionnaire. Then the researchers followed the men and women for about six years.

During the course of the study, the average participant gained half a pound (0.24 kilograms) each year.

The team found that participants who reported the lowest adherence to the Mediterranean eating pattern gained the most weight, while those most adherent were least likely to add pounds with age.

In fact, the strict Mediterranean eaters were 10 percent less likely to become overweight or obese by the end of the study, and had 24 percent lower odds of packing on more than 11 pounds (5 kilograms) over the study's first four years.

Iris Shai of Ben Gurion University, in Israel, noted that people who follow the Mediterranean diet are likely to be more satiated by the high fiber content of a typical meal and tend to consume fewer "empty calories."

"This study suggests that adherence to healthy dietary patterns are the key factor for avoiding the natural long-term yearly weight gain occurring during adulthood," Shai, who was not involved in the new study, told Reuters Health in an e-mail.

"This is extremely important in light of the critical issues raised by some fans of other dietary profiles who say that the Mediterranean diet, because of its high content of complex carbohydrates, could bring weight gain," Francesco Sofi of the University of Florence, Italy, and who was also not involved in the study, added in an e-mail to Reuters Health.

However, since this study only included university graduates, Sofi noted that the results might not be applicable to the broader population.

Beunza and his colleagues also point to some study limitations, including the possibility that the participants most adherent to the Mediterranean eating style were also more likely to follow other aspects of a healthier lifestyle. The researchers did analyze the data adjusting for a few of these possible confounding factors, such as smoking and exercise, and still reached the same results.

"The Mediterranean dietary pattern is a good user-friendly option to avoid falling into the obesity epidemic and all its unhealthy consequences," said Beunza.

"The more we study it," he added, "the more we learn about its benefits on health."