Logical Reasoning

PT126 · S1 · Q24 Advertisement: Researchers studied

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Advertisement: Researchers studied a group of people trying to lose weight and discovered that those in the group who lost the most weight got more calories from protein than from carbohydrates and ate their biggest meal early in the day.

Conclusion

Anyone who follows our diet is sure to lose weight

Evidence

Our diet provides more calories from protein than anything else and requires breakfast to be the biggest meal of the day. In a study, researchers found that the people who lost the most weight got more calories from protein and made their biggest meal early in the day.

Evaluation

This is the famous flaw of Correlation -> Causality. The author presents a study in which there was a correlation between “losing the most weight” and . She then assumes that making protein #1 and eating biggest meal early are the causal reasons why these people lost the most weight. What if they are just coincidental things that are correlated with the weight loss group, but something else was the real causal factor? (Maybe they ate fewer calories overall / exercised more / etc)

There is another famous flaw at work here: Sampling. Even if we accepted that “high protein / early big meal” caused the people in the study to lose weight, we don’t have to accept that this strategy would work for all people. The conclusion is boldly proclaiming

Goal

We either want a different explanation for why the “high protein / early big meal” group lost weight, or we want a reason to think that even though this diet worked for them it might not be sure to work for anyone who tries this diet.

24.

The reasoning in the advertisement is most vulnerable to criticism on the grounds that the advertisement overlooks the possibility that

  1. eating foods that derive a

    Out Of Scope Comparison

    Out Of Scope Comparison: “make one feel fuller” We’re not concerned with what type of food makes you feel fuller. This won’t help us argue that “#1 protein / early big meal” will not be sure to make you lose weight. At its best, maybe this answer gives someone a way to argue that a different diet might make it even easier to lose weight, but the conclusion is not comparative so that’s not a relevant objection.

    3% picked this

  2. a few of the people

    Too Weak: "a few"

    It doesn’t hurt the author if people who used an opposite technique (#1 carbs / late big meal) also had some weight loss. The author will still say, “Yes, but the ones who lost the most weight were #1 protein / early big meal.” In most statistics / study results that LSAT presents, we come away with a tendency that two things were connected. We can’t weaken that evidence by pointing out that some data points did not follow that trend. It is a weak idea that is fully compatible with the original premise.

    4% picked this

  3. the people in the group

    Unclear Impact

    Very tempting. This suggests that the author has pulled out the wrong causal factor from the study. It looks like activity level was a strong predictor of weight loss, whether or not people got #1 calories from protein or carbs. It has unclear impact on the conclusion, though, because the conclusion isn’t saying that #1 protein + early big meal is the best way to lose weight or the way that helps you lose the most weight. There’s nothing comparative about the conclusion, so the only way to beat the conclusion is to find a way to argue that if you did #1 protein + early big meal you would not necessarily lose weight.

    26% picked this

  4. Correct

    some people in the group

    Why this is right

    It’s very rare for an answer this weakly worded to be correct on Weaken, but a weak idea can still be devastating if you’re arguing against a strongly worded claim. If I say that “All men like football”, you can completely refute me with one man who doesn’t like football. Similarly, we can refute the conclusion that “anyone who follows this diet is sure to lose weight” with one counterexample of someone who followed the diet but didn’t lose weight. That’s what this answer provides. Even though “protein > carbs / early biggest meal” was associated with those who lost the most weight, it was also associated with people who lost no weight. Thus, it’s very hard for the author to act in her conclusion like following these two guidelines ensures that anyone will lose weight.

    Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

    65% picked this

  5. people who eat their biggest

    Opposite

    This seems to strengthen by supporting the author’s notion that eating big earlier in the day would lead to weight loss, by adding that it results in less snacking.

    2% picked this

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