AA007 好像没人讨论过？

AA007 题目：

The following appeared in the health section of a magazine on trends and lifestyles.

“People who use the artificial sweetener aspartame are better off consuming sugar, since aspartame can actually contribute to weight gain rather than weight loss. For example, high levels of aspartame have been shown to trigger a craving for food by depleting the brain of a chemical that registers satiety, or the sense of being full. Furthermore, studies suggest that sugars, if consumed after at least 45 minutes of continuous exercise, actually enhance the body’s ability to burn fat. Consequently, those who drink aspartame-sweetened juices after exercise will also lose this calorie-burning benefit. Thus it appears that people consuming aspartame rather than sugar are unlikely to achieve their dietary goals.”

我看了他的范文，还是看不明白其中的逻辑推理。范文如下：

In this argument the author concludes that people trying to lose weight are better off consuming sugar than the artificial sweetener aspartame. To support this conclusion the author argues that aspartame can cause weight gain by triggering food cravings, whereas sugar actually enhances the body’s ability to burn fat. Neither of these reasons provides sufficient support for the conclusion.

The first reason that aspartame encourages food cravings is supported by research findings that high levels of aspartame deplete the brain chemical responsible for registering a sense of being sated (sated, sating充分满足), or full. But the author’s generalization based on this research is unreliable. The research was based on a sample in which large amounts of aspartame were administered; however, the author applies the research findings to a target population that includes all aspartame users, many of whom would probably not consume high levels of the artificial sweetener.

The second reason that sugar enhances the body’s ability to burn fat is based on the studies in which experimental groups, whose members consumed sugar after at least 45 minutes of continuous exercise, showed increased rates of fat burning. The author’s general claim, however, applies to all dieters who use sugar instead of aspartame, not just to those who use sugar after long periods of exercise. Once again, the author’s generalization is unreliable because it is based on a sample that clearly does not represent all dieters.

To conclude, each of the studies cited by the author bases its findings on evidence that does not represent dieters in general; for this reason, neither premise of this argument is a reliable generalization. Consequently, I am not convinced that dieters are better off consuming sugar instead of aspartame.

范文说的第一个逻辑错误是说，基于食用high level of aspartame的人群所做的调查，并不能代表所有食用aspartame的人群，大部分人吃的aspartame量很少（不足以激发food craving）。这个我很理解的。

范文指出的第二个逻辑错误，我有点看不懂。说“The author's general claim, however, applies to all dieters who use sugar instead of aspartame, not just to those who use sugar after long periods of exercise. ”这里红色标出的部分是我最不能理解的地方：难道食用aspartame的人没有包括在整体减肥者之内吗？再说，前面说到对运动过后食用sugar的人进行调查发现sugar可以促进燃烧脂肪，后面consequently食用aspartame的人就没有这个燃烧的效果，这不也是在调查范围内的吗？文章为什么要用instead of 来把食用aspartame的人排除在外呢？

其实我觉得，这第二个逻辑错误应该是，调查研究只调查了那些连续运动过后食用sugar或aspartame的减肥者，这份样本不能represent所有减肥者，减肥者中不运动的人多了去啦！对于不运动的人，sugar的燃脂作用根本无法辨别的。如果文章把着力点放在“运动不运动”这一点上，是不是逻辑更清晰一点呢？

另外，这片AA还有没有其他逻辑错误？整个范文看起来好像很苍白似的。

恳请指点，谢谢！

are better off consuming sugar请 问 第 一 句 话 是 否 说 食 用 sugar要 好 过 前 者 ？

consumed after at least 45 minutes of continuous exercise

those who drink aspartame-sweetened juices after exercise will also lose this calorie-burning benefit

可 以 考 虑 这 两 个 比 较 是 否 同 条 件 。

第一句话是文章的结论，说sugar比aspartame好。

楼上加红的两句，我认为可以视作同条件。只不过，我不太清楚原文“Consequently”引导的那句话是研究结果还是作者想当然的推论。