Why Did Obese Men Lose Weight at High Altitude?

By Jacob Goldstein WSJ.com

Some time ago, 20 obese men traveled by cogwheel train and cable car to the awesomely named Umwelt Forschungsstation Schneefernerhaus, a research station (pictured) in the shadow of Germany’s highest mountain.

The men were the subjects of a study on altitude and weight loss. They were allowed to eat whatever they wanted during their week on the mountain, and their activity was restricted to slow walks through the research station.

They lost about three pounds during the week, on average. Four weeks after they went back home to the lowlands, they had kept most of the weight off. The study was published this week in the journal Obesity.

Of course, it’s hard to say anything definite when you have a 20-person study with no control group. Still, the researchers do have some interesting ideas about what the study, taken in the context of previous research, suggests.

During their time on the mountain, the men in the study ate less, their baseline metabolic rate went up and their levels of a hormone called leptin increased.

Some previous research has shown that metabolism gets faster at high altitude, though it’s not clear why. That alone would tend to make you lose weight, all other things being equal. What’s more, the rise in leptin — a hormone that plays a role in appetite — may have prompted the men to eat less, the authors say. Previous studies have suggested that the thin air at high altitude may prompt the body to crank out more leptin.

Photo via Umwelt Forschungsstation Schneefernerhaus