I am mostly interested in how strong you see the structure and in any flaws that you can spot in my counterarguments.
Thanks for all the comments!
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.”
Discuss how well reasoned... etc.In this argument the author recommends that people who consume the artifical sweetener aspartame will get more benefits from consuming sugar instead. In particular, the author concludes that sweeteners make dieting more difficult for them. The grounds for this action are twofold: First, high levels of aspartame impide the brain to create the sense of being full during meals. Second, sugar can accelerate the weight loss when consumed after doing exercise. However, stated in this way, the argument relies on a few unproven assumptions and fails to mention various key factors on the basis of which it could be evaluated. Therefore, the author´s argument is rather weak and problematic in several critical aspects.
The first issue to be addressed is the assumption that people frequently consume enough amount of sweetener aspartame as to reach an intake level that is considered high for this substance. Clearly, one could argue that even though some people like to make every drink they take during the day taste sweet, that doesn´t imply that everybody does similarly. For example, some people drink coffe only once a day in the morning and that is the unique time when the use any substance to improve the taste of any drink according to their liking. Considering this, the argument could have been much clearer if the author had explicitly stated how much quantity of the sweetener aspartame is necessary in order to traspassed the threshold after which the brain´s ability to make feel full is undermined.
Additionally, it is questionable whether people like taking sweet drinks after doing exercise. The author´s statement that because people consume drinks with sweetener aspartame rather than with sugar they lose the opportunity of burning even more fat after exercising is a stretch and not substantiated in any way. Just as likely, it is entirely possible that people drink flavoured protein shakes of whey powder mixed with water and don´t add any additional substances to improve its flavour. However, there is no guarantee for this to be the case, nor is there for the author´s instance to be. Nevertheless, had the argument provided evidence of what sorts of drinks, if any, people like drinking after doing exercise and the author´s line of reasoning would have been much more convincing. In addition, if the author had demonstrated that post-exercise drinks are usually accompanied by substances to make their flavour taste sweet, the argument could have been strengthened even further.
Finally, the author readily assumes that people consume sweetener aspartame rather than sugar mainly for the purpose of losing weight, but the lack of substantiation for this crucial assumptions does nothing but undermine the author´s argument. While it is clear that many people swap from sugar to sweeteners in order to reduce their daily calorie intake, it is not obvious how people who are not dieting would benefit from consuming sugar instead. Many people may consume sweetener to avoid suffering many of the disadvatanges that the sugar poses, such as high blood-pressure, hyperactivity, and brain-activity slowdown after several hours. As such, without examples of how people taking sweeteners would bypass all these problems the sugar posits, one is left with the impression that the claim that people would be better off consuming sugar has no legs to stand on.
In summary, the argument is not completely sound for the aforementioned reasons and hence, as it stands, it remains unsubstantiated and open to debate. In spite of that, the argument´s recommendation could have been considerably strengthened if the author had clearly mentioned the amount of aspartame that is considered high enough as to hinder the sense of being full, the sort of drinks that people frequently consume after exercising, and the benefits that sugar can bring to people who consume aspartame but are not dieting.
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