GMAT Essays (AWA)

Prompt:
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.

Essay:
In the preceding statement, the author claims that the use of aspartame over sugar actually hinders people's ability to achieve their dietary goals. Though his claim may have merit, the author presents a poorly reasoned argument based on several questionable premises and assumptions, and based soley on the evidence the author offers, the argument cannot be accepted as valid.

The primary issue with the author's reasoning lies with his unsubstantiated premises. The author claims that high levels of aspartame prevents the body from knowing it is full lacks the details that would allow us to accept this premise as valid evidence. The reader is left wondering what is considered to be high levels of aspartame and how does that compare to normal or average use of aspartame? The author also presents a study that sets out to prove that sugar helps burn calories after a workout, but fails to provide details on how the study was performed. Other factors such as type of exercise performed, physical condition of the subjects could also affect the after burn effect described. The author's premises, the basis for his argument, lack any legitimate evidentiary support and therefore renders his conclusion unacceptable.
The secondary point of concern with the author's reasoning is with his unproven assumptions. The author assumes that weight loss and dietary goals are one in the same. However what if someone is trying to put on weight by increasing their muscle mass. Increase mass and losing fat have different dietary requirements and therefore the proposed benefit of eating sugar wouldn't apply here. The author also fails to address the health risks associated with the consumption of too much sugar, especially for those who are already sensitive to sugar i.e. diabetics. The author weakens his argument by making assumptions and failing to provide explication of the links between dietary goals and weight loss he assumes exists.
In conclusion the author's illogical argument is based on unsupported premises and assumptions that renders his conclusion invalid. In order to change the readers mind on the issue, he would need to restructure his argument, fix the flaws in his logic, clearly explicate his assumptions and provide substantial evidence in support of his claim. Without these things, his argument would only convince a few misinformed people.