An investigator wants to assess the association between caffeine consumption and impaired glucose tolerance, a precursor to diabetes. A study is planned to include seventy participants. Each...

An investigator wants to assess the association between caffeine consumption and impaired glucose tolerance, a precursor to diabetes.  A study is planned to include seventy participants.  Each participant will be surveyed with regard to their daily caffeine consumption.  In addition, each participant will submit a blood sample which will be used to measure glucose level.

Identify the type of study proposed. Briefly explain why you think the study is of this type.

Indicate the study type's specific strengths and weaknesses.

Could the study describe be designed as a randomized clinical trial?  If so, briefly outline the study design.  If not, describe the barriers.