The study included more than 1,000 overweight or obese people in the United Kingdom, the Netherlands, Germany and Spain who were at risk for depression, but were not currently depressed.

Excess weight is often linked with depression, the researchers noted.
Half of the study participants took daily supplements containing folic acid, vitamin D, omega-3 fish oils, zinc and selenium. Half took a placebo pill.
Half were also counseled about their eating habits and urged to limit snacking and follow a healthy Mediterranean-style diet.
In a one-year follow-up, the researchers discovered that the supplements worked no better than the placebo in helping ward off depression.
Similarly, the counseling was not effective overall, though it seemed to help prevent depression in participants who attended a recommended number of sessions.
That suggests counseling works only if people get an adequate "dose" of therapy and make significant changes in their diet, according to the study
ed March 5 in the Journal of the American Medical Association.
"Because depression is such a common problem, finding effective and widely available ways to prevent depression at a population level is an important goal," said study co-author Ed Watkins.
He's a professor of experimental and applied clinical psychology at the University of Exeter in England.
"Diet and nutrition held promise as one means to reach large numbers of people. However, this trial convincingly demonstrates that nutritional supplements do not help to prevent depression," he said in a university news release.