Weight Loss May Not Improve Your Mood

NEW YORK (Reuters Health) Advertisements for weight-loss programs usually show cheery dieters delighted to be shedding their burden of excess pounds, but a new study finds that in the real world, over time, weight loss may be linked with worsening mood.

UK researchers following about 2,000 overweight and obese adults over four years found that people who lost 5% or more of their body weight had improved physical health but higher rates of depression.

We know that weight loss is so hard to achieve or maintain, so we wondered whether part of the explanation might be that the psychological effects aren’t entirely positive, said Jane Wardle, the study’s senior author and a researcher at University College London.

Our study isn’t definitive because we were comparing people in the general population who had lost weight with people who hadn’t it wasn’t a randomized trial. Wardle noted that many articles and products on weight loss imply that it will immediately make people feel better, but these findings show that may not be true. Overweight and obese adults are often told to lose weight to improve their health. According to a 2012 survey, about 60% of obese adults in the U.S. had tried to lose weight during the past year.

For overweight and obese people, weight loss is well known to lower the risks for a range of physical illnesses. However, research on the psychological benefits has been mixed. The researchers used information from 1,979 overweight and obese men and women who were part of the English Longitudinal Study of Ageing a large population study of U.K. adults aged 50 and older.

Nurses measured each participant's height, weight, and waist circumference, and questionnaires were used to assess mood. In addition, blood pressure and serum triglycerides were measured to determine cardiovascular risk. None of the participants was depressed when the study began. Since this was an observational study, the researchers didn’t give instructions or advice to lose weight, but they recorded whether or not the participants said they intended to lose weight.

After four years, 14% of the participants lost at least 5% of their initial body weight, or about 15 pounds on average. Another 71% had kept their weight stable, and 15% had gained more than 5% of their initial weight about 14 pounds on average.

The average age was highest in the weight-loss group, and there were more men and more wealthy participants in the weight-stable group. People in the weight loss group also tended to have more weight to lose than their counterparts. Psychological well-being deteriorated in all three groups, but members of the group who lost weight were 80% more likely to be depressed than those who maintained their weight.

The study doesn’t prove that losing weight caused depression, the authors note. It’s possible that depression caused some people to lose weight or that neither caused the other and that something else the participants had in common was responsible for the weight loss or the depression.

But Wardle said she has some idea why weight loss might be connected with depression. “To lose weight, a person has to eat less than they would like to, and possibly less than people around them, and losing out on the pleasure of food is bound to be tricky, even if there are compensations in terms of dropping a dress size and improving your health.

Maybe if we were more honest about the fact that it won’t necessarily make you feel good in the short term, people would gear themselves up for the challenge. We see people for a more abbreviated time a matter of weeks, but virtually everyone who leaves the (Duke Medical Center) leaves here in a much better mood, said Sha, who wasn’t involved in the new study. Everybody sees considerable improvement in their physical function, they see a considerable improvement in their mood and they all lose weight.