A nutritionist states: 'To maintain a healthy weight, individuals should drastically reduce their intake of carbohydrates. Carbohydrates are easily converted to fat in the body, leading to weight gain.' Which of the following principles, if valid, would cast the most doubt on the nutritionist's recommendation?
- ASome carbohydrates, such as fiber, are beneficial for digestive health.
- BIndividual metabolic rates vary, affecting how quickly food is converted to energy or stored as fat.
- CAny food consumed in excess of caloric needs will lead to weight gain, regardless of its macronutrient composition.
- DA balanced diet that includes all macronutrients is essential for overall health.
Show answer & explanationAnswer & explanation
Correct answer: C. Any food consumed in excess of caloric needs will lead to weight gain, regardless of its macronutrient composition.
The nutritionist attributes weight gain specifically to carbohydrates because they are 'easily converted to fat.' If principle A is true, then the problem isn't uniquely carbohydrates but *any* food consumed in excess. This undermines the specific focus on carbohydrates as the primary culprit for weight gain and the recommendation to *drastically reduce* them.
Why the other options are wrong
- A. This points out a benefit of some carbohydrates, but doesn't directly challenge the claim that carbohydrates contribute to weight gain when consumed in excess.
- B. Individual variation is a factor, but the nutritionist's recommendation is general. This principle doesn't invalidate the general mechanism (carbs to fat) but rather suggests individual differences in its magnitude, which doesn't cast *most* doubt on the core recommendation.
- D. While true, this is a general health principle and doesn't directly contradict the nutritionist's specific claim about carbohydrates and weight gain; it just offers a broader perspective.
Principle Application
Principle application questions require identifying a general rule or principle and determining how it applies to a specific scenario, or how a given principle might support or undermine an argument.
- Involves abstract thinking and generalization.
- Requires understanding the core logic of the principle.
- Can be used to strengthen, weaken, or justify an argument.
Memory trick: Does this rule fit the case, or throw it out of place?