Final answer:
The statement supports Hill's criterion for assessing causation, specifically criterion number 2: Temporal relationship.
Step-by-step explanation:
The statement "One of the strengths of this study is that the condition of being overweight was established before cancer developed" supports Hill's criteria for assessing causation, specifically criterion number 2: Temporal relationship. This criterion states that the cause (overweight) must occur before the effect (cancer).
In this case, the study shows that being overweight was established before cancer developed, indicating a temporal relationship between the two.