Obese People Lose Weight at High Altitudes

Here's a possible future diet tip: Move to a mountaintop.

In a recent study, obese individuals who spent time at a mountain facility at high altitudes lost weight without going on a diet. And they kept the pounds off for at least four weeks once they returned to normal altitudes.

The researchers suspect part of the weight loss can be attributed to the thin air, which may have decreased participants' appetites and increased their metabolism, meaning they burned more calories sans a workout. While at high altitudes, the obese subjects also showed an increase in levels of leptin, a hormone that when present can make one feel full.

But don't head for the hills just yet - these findings are very preliminary and were only tested in a small sample of people. Further research is needed to confirm the weight-loss effect, and understand why it may occur.

The study is detailed in the Feb. 4 issue of the journal Obesity.

Mountain Living

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.

But 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 a bump in metabolism. On average, the participants' metabolism increased, meaning their bodies burned more calories 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 there leptin levels at altitude, the researchers say 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.

Holidays in the Mountains

Interestingly, the participants maintained their reduced weight after they had returned to normal altitude 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 off the pounds. The researchers aren't sure about the cause of this extra activity, but they think 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, Lippl told LiveScience.

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. He plans to do another study involving more participants over a longer period of time to see if mountain stays can help promote long lasting weight loss.

source: www.foxnews.com

Compounds in Green Tea May Protect Against Common Eye Diseases

Green tea has increasingly become one of the world’s most popular beverages, and for good reason. The purported health benefits of green tea are nothing short of amazing. It appears to reduce the risk for a wide range of diseases, from bacterial or viral infections to chronic degenerative conditions including cardiovascular disease, stroke, cancer, diabetes mellitus, rheumatoid arthritis, osteoporosis, and periodontal disease. Green tea can also be used as a weight loss tool when used alongside a healthy diet. Researchers in Japan have found that drinking five cups of green tea a day can burn up to 70 to 80 calories, which translates to about seven pounds a year. And recently, researchers at the Chinese University in Hong Kong discovered yet another benefit of drinking this health-promoting brew—it could protect against common eye diseases such as glaucoma.

For their study, published in the current issue of the Journal of Agricultural and Food Chemistry, Chi Pui Pang and colleagues gave laboratory rats green tea extract and then analyzed their eye tissue. The researchers found that different parts of the eye absorbed varying amounts of catechins, antioxidants which are believed to prevent damage caused by oxidation. The retina, the part of the eye responsible for sensing light, had the highest concentration of the antioxidants, while the least amount was found in the cornea, the clear outer layer of the eye. The antioxidant activity lasted for up to 20 hours after consumption of green tea extract. “Our results indicate that green tea consumption could benefit the eye against oxidative stress,” the authors concluded. Oxidative stress leads to retinal diseases like glaucoma and age-related macular degeneration (AMD).

Green tea is the least processed, made by briefly steaming the just harvested leaves, rendering them soft and pliable and preventing them from fermenting or changing color. After steaming, the leaves are rolled, then spread out and dried with hot air or pan-fried in a wok until crisp. Because of green tea’s minimal processing, its catechins, especially epigallocatechin-3-gallate (EGCG), which is believed to be responsible for most of the health benefits linked to green tea, are more concentrated. It wasn’t known until now, however, if the catechins were able to make their way from the mouth, through the gastrointestinal system, and be absorbed into the tissues of the eye. More studies will be needed to confirm the protective effect in humans.

Adding green tea to your diet is simple and inexpensive. It also provides a healthful alternative to sugar-and-chemical laden soft drinks which are helping to fuel soaring rates of diabetes and obesity. And if you are like millions of Americans who have a hard time getting the recommended number of servings of fruits and veggies, two cups of green tea equals one serving. You could also try this great recipe for sautéed vegetables in green tea:



2 tablespoons canola oil

2 teaspoons finely chopped fresh red chili pepper

1 teaspoon grated lemon peel

1 teaspoon loose tea leaves, preferably gunpowder

4 cups broccoli florets

1 cup yellow zucchini or summer squash, cut into 1/4 inch diagonal slices

1/2 cup brewed green tea
1/4 cup red bell pepper squares (1 inch)

salt and pepper to taste

Add the oil to a nonstick wok or cooking pan over medium-heat and swirl the pan to coat. Add the chili pepper, lemon peel and tea leaves. Stir fry until fragrant for about 1 minute. Add the broccoli florets and zucchini. Stir fry for 2 minutes. Add the tea and bell pepper, season with salt and pepper. Cook until most of the liquid evaporates and serve hot.

Makes 4 servings.

Source: Cooking with Green Tea