Question

5. A study was performed to compare the e↵ect of dietary supplementation with a low-fibre refined wheat product on the serum cholesterol of 20 healthy participants aged 23-49 years. Each subject had a cholesterol level measured at baseline and then was randomly assigned to receive either a high-fibre or lowfibre diet for 6 weeks. A 2-week period followed during which no supplements were taken. Participants then took the alternative supplement for a 6-week period. The results are shown below:

n    Baseline    High fiber low fiber difference(high fibre - low fibre) difference(high fibre - baseline)    difference(low fibre-baseline)

total Cholesterol(mg/dl)    20 186 +-31    172+-28 172+-25 -1    -14    -13

(-8, +7) (-21,7)    (-20,7)
(a) Does the high-fibre diet change cholesterol level from baseline? Justify your answer.

(b)Does the low-fibre diet change cholesterol level from baseline? Justify your answer.

(c)Is the change due to the high-fibre diet di↵erent from the change due to the low-fibre diet? Justify.

Answer 1