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An article in the Journal of Academy of Nutrition and Dietetics reported on a study of diet in subjects with moderate to severe acne. Read the excerpts from the abstract and then complete parts?(a) and?(b) below.

?Methods: Sixty-four participants?(no acne, n=?32; ?moderate/severe acne, n=?32) were included in this study. Participants completed a?5-day food?record, had blood drawn and completed a questionnaire to evaluate?food-aggravated acne beliefs and?acne-specific quality of life.

?Results: Participants with?moderate/severe acne consumed greater total carbohydrate compared to participants without acne. Participants with?moderate/severe acne had greater insulin compared to participants without acne. Although there were no differences between?groups, 61% of participants reported?food-influenced acne.

a. Was this a controlled experiment or an observational?study? Explain how you know.

A.

This was a controlled experiment. There was a random assignment to?treatment/control groups. The subjects kept a food diary and had their blood drawn.

B.

This was a controlled experiment. There was no random assignment to?treatment/control groups. The subjects kept a food diary and had their blood drawn.

C.

This was an observational study. There was no random assignment to?treatment/control groups. The subjects kept a food diary and had their blood drawn.

D.

This was an observational study. There was a random assignment to?treatment/control groups. The subjects kept a food diary and had their blood drawn.

b. Assuming the study was properly?conducted, can we conclude that higher consumption of carbohydrates causes more severe?acne? Explain.

We ?

can

cannot

make a?cause-and-effect conclusion since ?

this was a controlled experiment.

61% of participants reported food-influenced acne.

this was a randomized design.

this was an observational study.

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