Stress may have only small impact on weight

"Small," as in none.

Despite the common belief that stress causes people to pack on the pounds, a new research review finds that, on average, stress has little long-term effect on weight.

The results are surprising, researchers say, given the widespread notion that stress - by causing people to reach for junk food or skimp on exercise, for example -- is an important factor in weight gain.

No they're not.

Note that even if stress is related to weight gain, it can only happen if one consumes more Calories than one burns.

When the investigators pulled together 32 previously published studies on the question, however, they found the majority showed no association between people's stress levels and their weight gain over several years.

When the researchers combined the studies' results -- in what is known as a meta-analysis -- there was only a modest association overall between stress and weight gain.

"When we started this meta-analysis, we assumed that there would be a substantial association between stress and obesity, since the popular view is that stress contributes to weight gain," co-researcher Dr. Andrew Steptoe, of University College London in the UK, told Reuters Health in an e-mail.

"But when we looked carefully at well-controlled scientific studies," he said, "effects were surprisingly small."

Again, no surprise, here.

"The general message," Steptoe said, "is that, based on the best current scientific research, stress is not likely to play a major role in increasing body weight or obesity for most people."

For sure.