Weight Loss

Altitude Training & Weight Loss

This study is detailed in Obesity (2010) 18, 675-681.

Previous research has found that people tend to lose weight at high altitudes. But most of these studies were done in athletes and hikers who engaged in lots of physical activity. The question remained, would the same effect hold true for obese subjects who were relatively sedentary?

To find out, Dr. Florian Lippl, of Ludwig Maximilians University in Munich, Germany, and his colleagues enrolled 20 obese male participants, with an average weight of 230 pounds (105 kg). They monitored the subjects for one week at low altitudes, looking at what they ate, and how much they walked. Then, the participants spent two weeks in an air-conditioned research facility, located on a mountain at about 8,700 feet (2,650 m) above sea level. The participants had no restrictions in what they could eat, but they weren’t allowed to exercise rigorously. After their stay, the subjects were brought down to normal altitude, and followed up for four weeks.

On average, the participants lost about 3.3 pounds (1.5 kg) while at altitude, Lippl said. This decrease might not seem like much, but it was statistically significant compared with the starting weight.

The researchers think some of the loss can be explained by the fact that the subjects naturally ate less on the mountain, cutting back by 734 calories per day on average.

But a change in diet alone couldn’t account for all of the weight loss. The researchers think some of the decrease had to do with an increase in metabolism. On average, the participants’ metabolic rates increased, meaning their bodies burned more energy at rest, without requiring extra movement.

The hunger hormone

In the case of this study, there may be a physiological reason why the participants ate less. The researchers measured levels of a hormone called leptin, which plays a role in controlling appetite. An increase in your leptin levels means you feel full, while a decrease makes you hungry. Since the obese subjects showed a general increase in their leptin levels at altitude, the researchers suggest changes in this “hunger hormone” could have been a factor.

Though Lippl and colleagues aren’t sure why leptin levels increased on the mountain, they speculate the thin air may have something to do with it. Studies have shown that when human cells are put in a low-oxygen environment (similar to the air at high altitude) they produce more leptin.

Study participants also saw a significant decrease in diastolic blood pressure and a trend towards lower systolic blood pressure following the altitude sojourn.

Holidays in the mountains

Interestingly, the participants maintained their reduced weight after they had returned to sea level and stayed there for four weeks, a finding the researchers did not expect. But the subjects walked a little bit more, which may have helped keep the weight off. The researchers aren’t sure about the cause of this extra activity, but they believe it may be related to the high altitude “training effect,” the performance boost athletes experience when they train at high altitudes and race closer to sea level, in this case making physical activity easier for the obese subjects, Lippl suggested.

Without the stress of the low-oxygen, mountain environment, the obese patients may have felt fitter, and were able to exert themselves more, Lippl said.

So could future diet regimes involve skiing vacations?

“With a little humor, I tell my patients now, if they want to take holidays, they should think of mountain holidays rather than spending their holidays at the sea,” Lippl said. But in seriousness, Lippl says, the study is really a starting point for further research into the effects of altitude exposure on weight loss in overweight patients.

Further reading:

  1. Hamad N., Travis, SP. Weight loss at high altitude: pathophysiology and practical implications. Eur. J. Gastroenterol. Hepatol 2006: 18:5-10
  2. Nair CS, Malhotra MS, Gopinath PM. Effect of altitude and cold acclimatisation on the basal metabolism in man. Aerosp Med 1971:42:1056-1059.
  3. Tschop m. Strasburger CJ, Hartmann G, Biollaz J, Bartsch P: Raised Leptin concentrations at high altitude associated with loss of appetite. Lancet 1998:352:1119-1120.
  4. Westerterp KR. Energy and water balance at high altitude. News Physiol Sci 2001:16:134-137.
  5. Shukla V. Singh SN, Vats P et al. Ghrelin and leptin levels of sojourners and acclimatized lowlanders at high altitude. Nutr Neurosci 2005:8:161-165
  6. Vats, Singh SN, Shyam R et al: Leptin may not be responsible for high altitude anorexia. High Alt Med Biol 2004:5:90-92.
  7. Woolcott OO, Castillo OA, Torres J, Damas L, Florentini E. Serum leptin levels in dwellers from high altitude lands. High Alt Med Biol 2002:3:245-246.
  8. Barnholt KE, Hoffman AR, Rock PB et al. Endocrine responses to acute and chronic high altitude exposure (4300 metres): modulating effects of caloric restriction. Am J Physiol 2003:88:506-518.
  9. Schobersberger W, Schmid P, Lecheitner M et al. Austria Moderate Altitude Study 2000 (AMAS 2000). The effects of moderate altitude (1700m) on cardiovascular and metabolic variables in patients with metabolic syndrome. Eur J Appl Physiol 2003:88:506-518.
  10. Netzer NC, Chytra R, Kupper T. Low intense physical exercise in normobaric hypoxia leads to more weight loss in obese people than low intense physical exercise in normobaric sham hypoxia. Sleep Breath 2008:12:129-134.
  11. Dominguez Coello S. Cabrera De Leon A. Bosa Ojeda F et al. High density lipoprotein cholesterol increases with living altitude. Int J Epidemiol 2000:29:65-70.