​Can You Control Your Metabolism With Your Mind?

Well... maybe. In this intriguing video piece, NPR's Alix Spiegel discusses the work of Columbia psychologist Alia Crum, whose research suggests that food labels have a placebo effect on the way our bodies respond to food and experience hunger. But to what extent do these results mean that we can think ourselves thin?

Crum designed an experiment to investigate the link between what we think we're eating, how full we feel and how our bodies respond. First, she made some milkshakes. Then, she labeled each shake as either "Sensishake: Fat Free, Guilt Free, 104 Calories" or "Indulgence: Decadence You Deserve, 620 Calories." In reality, all the shakes were around 300 calories. Test subjects were asked to drink the milkshakes while nurses monitored their blood levels of ghrelin, a hormone that increases with hunger, decreases after a meal, and affects the rate of our metabolism.

"Crum discovered that those who believed they were drinking the indulgent shake responded as if their bodies had eaten three times more," explains Spiegel. "So what people believed about their milkshake came true. If they thought it was fattening, they felt they'd eaten more and their digestion was affected. Their ghrelin levels dropped three times more."

As the NPR video points out, Crum's findings suggest that while it may not matter as much as what we eat, how we think about what we eat could play a significant role in how our bodies process food. There's obviously something very appealing about that, but it warrants a good measure of skepticism. For one thing, Crum's study apparently lacked a control group – that is, a group of test subjects who were not intentionally deceived with either rhetoric or calorie counts.

The video's advice to try "eating healthy food with an indulgent mindset," then, also falls flat – especially when you consider that none of the test subjects knew i) the nutritional profile of what they were eating, or ii) to approach the meal with any mindset but the one they were tricked into adopting. The test was examining a placebo effect based on deception – not a conscious one based on intentional visualization, or any other deliberate mind-body technique.

It's still a fascinating first look at how our beliefs could affect our physiology, but, as Crum herself says, more tests need to be conducted.

Check out the full story over at NPR.