Passage Summary: A commentator claims that because the average weight of all kids barely changed, it's impossible for there to be a surge in the number of obese kids.

Conclusion: The percentage of children who are obese has not significantly increased.

Reasoning: The average weight of all children has only increased by one pound over the last eight years.

Analysis: This argument suffers from a classic 'average vs. distribution' flaw. An average can remain stable even if the extremes of a group change drastically—for instance, if some children became much heavier while others became slightly lighter. You are looking for an answer choice that uses a lack of change in a general average to incorrectly conclude that there hasn't been a significant shift in a specific sub-category.