Researchers reported in the Journal of the American Medical Association (JAMA) that overweight women who lost as little as five pounds handled daily activities more easily and had fewer aches and pains.

Gaining as little as five pounds had the reverse effect in normal-weight and overweight women, the researchers said. The four-year study of more than 40,000 nurses, aged 46 to 71, is one of the few to show that small changes in weight can have a big effect on quality of life.

The study reports that overweight women who shed some weight tend to function better physically and had more vitality and less pain and that modest weight loss can give people an emotional boost. It gives them the kind of self-confidence they need to move ahead with their life, perhaps to earn promotions, to change jobs, to improve relationships.

Most research on overweight people has focused on dire long-term risks - diabetes, high blood pressure, heart disease, stroke and cancer. However, the majority of these people don't end up getting those diseases. But daily things like being able to walk up stairs can affect everyone's lifestyle.

A separate study in JAMA reported that obese women are more than six times as likely as lean women to have a silent inflammation in their arteries that may boost their already elevated risk of heart disease. The study involved more than 16,000 Americans.

The results were first reported in April 2001 at a meeting in Washington by obesity researcher Marjolein Visser of Vrije University in Amsterdam, the Netherlands.