Can Your Thoughts Affect Your Weight?

By Alix Spiegel
Source: National Public Radio

The holidays are finally over and your waistline is as overstretched as your credit card. It's time to take action! What should you do?

A) Hit the gym.

B) Make a solemn pledge to never ingest another sweet for as long as you live.

C) Hit the gym and make a solemn pledge to never ingest another sweet for as long as you live, or…

D) Sit around on the couch eating chocolate bonbons while genuinely believing that you are getting a lot of rigorous exercise.

The answer to this multiple-choice quiz might not be as straightforward as you think. In fact, a recent study by Harvard psychologist Ellen Langer seems to challenge our basic assumptions about the relationship between the physical body and the mind — and perhaps even our assumptions about the nature of objective reality itself. It certainly challenges our assumptions about the limits of the placebo effect.

Langer is a researcher who has published several important and provocative studies. In this study, she decided to look at whether our perception of how much exercise we are getting has any effect on how our bodies actually look. To do this, she studied hotel maids.

As any casual observer of the hospitality industry knows, hotel maids spend the majority of their days lugging heavy equipment around endless hallways. Basically, almost every moment of their working lives is spent engaged in some kind of physical activity.

But Langer found that most of these women don't see themselves as physically active. She did a survey and found that 67 percent reported they didn't exercise. More than one-third of those reported they didn't get any exercise at all.

"Given that they are exercising all day long," Langer says, "that seemed to be bizarre."

Perceptions Change Your Body and Weight

What was even more bizarre, she says, was that, despite the fact all of the women in her study far exceeded the U.S. surgeon general's recommendation for daily exercise, the bodies of the women did not seem to benefit from their activity.

Langer and her team measured the maids' body fat, waist-to-hip ratio, blood pressure, weight and body mass index. They found that all of these indicators matched the maids' perceived amount of exercise, rather than their actual amount of exercise.

So Langer set about changing perceptions.

She divided 84 maids into two groups. With one group, researchers carefully went through each of the tasks they did each day, explaining how many calories those tasks burned. They were informed that the activity already met the surgeon general's definition of an active lifestyle.

The other group was given no information at all.

One month later, Langer and her team returned to take physical measurements of the women and were surprised by what they found. In the group that had been educated, there was a decrease in their systolic blood pressure, weight, and waist-to-hip ratio — and a 10 percent drop in blood pressure.

One possible explanation is that the process of learning about the amount of exercise they were already getting somehow changed the maids' behavior. But Langer says that her team surveyed both the women and their managers and found no indication that the maids had altered their routines in any way. She believes that the change can be explained only by the change in the women's mindset.

Essentially, what Langer is talking about is a placebo effect. She says that if you believe you are exercising, your body may respond as if it is. It's the same as if you believe you are getting medication when you are actually getting a sugar pill — your body can sometimes respond as if a placebo is actually working.

The implication is that the "objective reality" of the physical body is not as immovable as we might have assumed. Hence, the theoretical possibility that, if done with genuine conviction, one might be able to sit around eating chocolate and still lose weight.

Placebo Effect Limited?

But Martin Binks, director of behavioral health at the Duke Diet and Fitness Center in North Carolina, is skeptical of Langer's conclusion, even though he is impressed with the physical changes in the maids.

"There's a very high likelihood that [the maids] behaved differently after they received that information," he says, "and they were being more active and eating more healthfully. And that resulted in their improvements in health."

But Binks has a more substantive criticism. He does not believe that placebos are capable of producing the kind of objective change in the physical body that Langer is claiming.

"Generally what placebos work on is subjective types of findings," he says.

In other words, a placebo can help change something like your perception of pain or perhaps your sense of whether you feel depressed, but it can't do something objective like shrink a tumor or cut three pounds off your waistline.

Or can it?

Howard Brody has spent years looking at this issue. He says that a number of relatively new studies challenge the old assumption that the placebo effect alters only subjective perception. He is the director of the Institute for the Medical Humanities at the University of Texas Medical Branch and the author of the book, The Placebo Response.

For example, Brody notes one study where researchers gave asthmatic patients a drug that actually makes asthma worse. When they gave the drug to the patients, they told them that it relieves asthma.

"A significant number of those patients said that my asthma got better when you gave me the drug," Brody says, "and they measured better when you measured the lung findings.

"So the idea that the placebo effect applies only to subjective things is really one that we have to dismiss."

So maybe it really might be possible to sit on the couch eating chocolates and lose weight. I, for one, am certainly willing to sacrifice and give it the old college try.

RELATED ARTICLE: Can Imaginary Exercise Make You Fit?

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