Previous studies have demonstrated weight loss in athletes and normal-weight subjects at high altitude, but this study focussed on the impact of altitude on overweight people for whom weight loss is desirable.

Researchers from Germany took 20 obese men to a high altitude location for one week. No changes were made to the men's food availability or exercise routine in an attempt to isolate the impact of altitude on weight.

After one week, the participants were eating less, had lost weight and had a lower diastolic BP. These changes were still present four weeks after returning to a lower altitude.

Writing in Obesity, the researchers said that low levels of oxygen found at high altitude may cause a rise in the hormone leptin which is thought to suppress appetite. However, they say that more research is needed to explore the link between altitude and weight loss.

‘Obesity and associated disorders are a growing problem in many Western societies, and effective treatments remain elusive,' they said.

‘The clarification of mechanisms leading to weight loss at high altitudes might provide new tools for treating obesity in future.'