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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.
參考譯文：
美國的一個飲食指南建議，人們每日平均攝入的熱量不應該超過2,000卡。多吃含纖維的食品，避開飽和脂肪，把每日的鈉攝入量控制在2,300毫克以下。對于女性來說，規則還要嚴格一點兒：最近的一項研究表示，女性應該每天都運動60分鐘，才能在年齡增長的同時仍保持體重。
要計算一個人的標準體重，醫療專業人員依靠的是一種考慮了身高和體重的指標，也就是所謂的“體重指數”(BMI)。BMI在18.5到24.9之間是正常的。“超重”指的是BMI在25到29.9之間。BMI在30或以上的人則屬于肥胖范圍。人們被大量有關體重和健康的信息、建議和規則淹沒了。要想了解各種醫學和營養研究幾乎是不可能的（有些甚至是互相矛盾的）。至少，要堅持按照這些建議做是很難的。
不過，以下這些消息可能會讓你的壓力減少一些。
盡管專家們一致認為肥胖是一種嚴重的健康問題，會引發很多疾病，但超重幾磅和肥胖之間是有區別的。美國飲食協會(American Dietetic Association)注冊營養師、發言人甘斯(Keri Gans)說，僅僅是因為某個人稍微超重了，并不意味著他不健康。 實際上，研究人員和醫生也開始明白，吃健康食品、進行鍛煉比你稱體重時體重計上的讀數重要得多。
目前正在出現一類新的研究，他們認為超重幾磅沒有什么風險，甚至可能會帶來一些好處。實際上，與那些所謂的體重“正常”的人相比，超過標準體重10到15磅的人看起來并沒有更大的死亡風險。其他研究則顯示，超重的人死于癌癥或心血管疾病的可能也并不比普通人高。 此外，稍微超重可能會幫助你避免患上骨質疏松。它還能讓你看起來更加年輕。
澳大利亞的一項研究發現，70多歲的人中，超重的人比體重正常的人10年內死亡的可能性要小。這可能意味著，超重幾磅或許能夠增強人們對疾病和損傷的抵抗力。這項研究發表在2月份的《美國老年醫學會期刊》(Journal of the American Geriatrics Society)上。研究對約9,000名男女進行了考察。研究的首席科學家、西澳大學(University of Western Australia)老年醫學教授費力克(Leon Flicker)說，研究還發現，每周鍛煉兩次、每次進行一點運動就足以降低久坐生活方式所帶來的一些不良影響。
研究骨質疏松的醫生們認為超重10磅能帶來一些好處：皮下脂肪可以產生雌激素，它可以幫助增強骨密度。美國國家骨質疏松癥基金會(National Osteoporosis Foundation)臨床主任、哥倫比亞大學醫學教授考斯曼(Felicia Cosman)說，多承受一點重量它還可能強化骨骼。考斯曼說，女性不用為超重10到15磅而擔心，特別是若脂肪不是集中在腹部的話。
