新東方雅思網(wǎng)校

The study is worth a closer look to see what it did and did not prove.

這項(xiàng)研究值得我們?nèi)ゼ?xì)究它證明了什么，沒有證明什么。

Researchers at Stanford University took more than 600 people (which is huge for a nutrition study) aged 18 to 50 who had a body mass index of 28 to 40 (25-30 is overweight, and 30 and over is obese). The study subjects had to be otherwise healthy. They couldn’t even be on statins, or drugs for Type 2 diabetes or hypertension, which might affect weight or energy expenditure. They were all randomly assigned to a healthful low-fat or a healthful low-carbohydrate diet, and they were clearly not blinded to which group they were in.

斯坦福大學(xué)(Stanford University)的研究人員挑選了600多名(這個數(shù)字對營養(yǎng)學(xué)研究來說堪稱巨大)年齡在18到50歲，身體質(zhì)量指數(shù)在28到40之間(25到30之間為超重，30或以上為肥胖)的研究對象。他們在其他方面必須保持健康，甚至不能服用他汀類藥物，也就是治療2型糖尿病或高血壓的藥物。這些藥物可能會影響體重或能量消耗。所有人被隨機(jī)分到健康低脂飲食組或健康低碳水化合物飲食組， 他們顯然 知道自己屬于哪一個組。

All participants attended 22 instructional sessions over one year in groups of about 17 people. The sessions were held weekly at first and were then spaced out so that they were monthly in the last six months. Everyone was encouraged to reduce intake of the avoided nutrient to 20 grams per day over the first eight weeks, then participants slowly added fats or carbohydrates back to their diets until they reached the lowest level of intake they believed could be sustained for the long haul.

在一年時間里，所有參與者以大約17人一個小組的形式上了22次指導(dǎo)課。這些課程一開始每周一次，然后拉開間距，到最后六個月變成每月一次。在前八周，每個人都被鼓勵將應(yīng)避免的營養(yǎng)物質(zhì)的攝入量降低到一天20克，然后參與者慢慢恢復(fù)各自飲食中的脂肪或碳水化合物攝入量，直到達(dá)到他們認(rèn)為可以長期維持的最低攝入量。