It may run counter to advice from almost every quarter, but a Finnish study suggests that losing weight may not be wise for overweight people.

The results indicate that the likelihood of dying over a 24-year period associated with deliberate weight loss is on a par with that associated with weight gain among overweight or obese individuals.

The researchers propose studies to “assess if the optimal strategy among already overweight individuals could be to avoid further weight gain. If this is true,” they add, “it puts a major emphasis on the need for prevention of development of overweight and obesity.”

Previous studies have reported a link between weight loss and increased death risk. Dr. Jaakko Kaprio, from the University of Helsinki, and colleagues theorized that this may be due to other, ultimately fatal, diseases that also caused unintentional weight loss.

To look into the possibility, the team studied participants in the Finnish Twin Cohort, but excluded subjects with any recognized chronic disease that could induce weight loss.

The subjects, who were born in Finland before 1958, were surveyed in 1975 and in 1981. The 1975 questionnaire asked about current attempts to lose weight, while the 1981 questionnaire documented changes in weight. The subjects were followed until death or the end of 1999.

According to the investigators’ report in PLoS Medicine, the final group included 2957 subjects who were overweight or obese in 1975. Two hundred sixty-eight of these subjects died during follow-up.

Individuals who lost or gained weight between 1975 and 1981 were roughly 40 percent more likely to die than those who kept a steady weight. Moreover, intentional weight loss raised the risk of death by 87 percent compared with maintaining a steady weight.

The researchers discuss numerous possibilities to explain their findings, and say more research is needed before the results “can be used as basis for advice about intentional weight loss in the large population of otherwise healthy overweight and obese individuals.”

SOURCE: PLoS Medicine, June 2005.