手机版
People should consume, on average, no more than 2,000 calories a day, according to U.S. dietary guidelines. Eat fiber. Avoid saturated fat. And keep your sodium intake under 2,300 milligrams a day. For women, the rules are even tougher: A recent study says women should exercise 60 minutes per day, every day, in order to just maintain their weight as they age.
To calculate how much individuals should weigh, health-care professionals rely on a measurement that considers height and weight, and is known as the 'Body Mass Index' (BMI). A BMI of 18.5 through 24.9 is considered normal. 'Overweight' is considered having a BMI of 25 to 29.9. A person with a BMI of 30 or higher qualifies as obese.People are awash in information, recommendations and rules surrounding weight and wellness. It's almost impossible to keep track of the medical and nutritional studies (some of which are contradictory). And it's difficult, at a minimum, to adhere to them.
But here's some news that may take off a bit of the pressure.
While experts agree that obesity is a serious health issue with widespread medical implications, there is a difference between carrying a bit of extra fat and being obese. 'Just because someone is slightly overweight doesn't mean they're not healthy,' says Keri Gans, a registered dietician and spokeswoman for the American Dietetic Association. Indeed, researchers and doctors are starting to understand that eating healthy foods and getting exercise can matter more than the number that appears when you step on the scale.
A body of research is emerging that suggests that there's little risk to carrying a few extra pounds. And there may even be some benefit. Indeed, people who are 10-to-15 pounds overweight appear to have no greater risk of dying than those of so-called 'normal' weight. Other studies have shown that those who are overweight are no more likely to die from cancer or cardiovascular disease. Also, being a little overweight may help stave off osteoporosis. And it can make you look younger, too.
An Australian study found that people in their 70s who were overweight were less likely than those of normal weight to die during a 10-year time span. This could indicate that a little extra weight might fortify people against illness and injury as they age. The study, which was published in February in the Journal of the American Geriatrics Society, studied about 9,000 men and women. It also found that 'a little physical activity' twice a week was enough to ameliorate some of the harmful effects of a sedentary lifestyle, says Leon Flicker, the study's chief scientist and a professor of geriatric medicine at the University of Western Australia.
Doctors who study osteoporosis see some benefits to being 10 pounds overweight: Subcutaneous fat produces estrogen which can help increase bone mass. And it might strengthen a skeleton to carry a bit of extra weight, says Felicia Cosman, clinical director of National Osteoporosis Foundation and a professor of medicine at Columbia University. 'Women should not worry if they are 10 to 15 pounds overweight, particularly if the fat is not concentrated in [the] belly,' Dr. Cosman says.
参考译文：
美国的一个饮食指南建议，人们每日平均摄入的热量不应该超过2,000卡。多吃含纤维的食品，避开饱和脂肪，把每日的钠摄入量控制在2,300毫克以下。对于女性来说，规则还要严格一点儿：最近的一项研究表示，女性应该每天都运动60分钟，才能在年龄增长的同时仍保持体重。
要计算一个人的标准体重，医疗专业人员依靠的是一种考虑了身高和体重的指标，也就是所谓的“体重指数”(BMI)。BMI在18.5到24.9之间是正常的。“超重”指的是BMI在25到29.9之间。BMI在30或以上的人则属于肥胖范围。人们被大量有关体重和健康的信息、建议和规则淹没了。要想了解各种医学和营养研究几乎是不可能的（有些甚至是互相矛盾的）。至少，要坚持按照这些建议做是很难的。
不过，以下这些消息可能会让你的压力减少一些。
尽管专家们一致认为肥胖是一种严重的健康问题，会引发很多疾病，但超重几磅和肥胖之间是有区别的。美国饮食协会(American Dietetic Association)注册营养师、发言人甘斯(Keri Gans)说，仅仅是因为某个人稍微超重了，并不意味着他不健康。 实际上，研究人员和医生也开始明白，吃健康食品、进行锻炼比你称体重时体重计上的读数重要得多。
目前正在出现一类新的研究，他们认为超重几磅没有什么风险，甚至可能会带来一些好处。实际上，与那些所谓的体重“正常”的人相比，超过标准体重10到15磅的人看起来并没有更大的死亡风险。其他研究则显示，超重的人死于癌症或心血管疾病的可能也并不比普通人高。 此外，稍微超重可能会帮助你避免患上骨质疏松。它还能让你看起来更加年轻。
澳大利亚的一项研究发现，70多岁的人中，超重的人比体重正常的人10年内死亡的可能性要小。这可能意味着，超重几磅或许能够增强人们对疾病和损伤的抵抗力。这项研究发表在2月份的《美国老年医学会期刊》(Journal of the American Geriatrics Society)上。研究对约9,000名男女进行了考察。研究的首席科学家、西澳大学(University of Western Australia)老年医学教授费力克(Leon Flicker)说，研究还发现，每周锻炼两次、每次进行一点运动就足以降低久坐生活方式所带来的一些不良影响。
研究骨质疏松的医生们认为超重10磅能带来一些好处：皮下脂肪可以产生雌激素，它可以帮助增强骨密度。美国国家骨质疏松症基金会(National Osteoporosis Foundation)临床主任、哥伦比亚大学医学教授考斯曼(Felicia Cosman)说，多承受一点重量它还可能强化骨骼。考斯曼说，女性不用为超重10到15磅而担心，特别是若脂肪不是集中在腹部的话。
