The time of day when the stress hormone peaks shifts from daytime to nighttime in mice eating a high-fat diet, which is the opposite of what normally happens.
Scientific Claim
Female ICR mice on a high-fat diet (60% kcal from fat) for four weeks exhibit a phase shift in the peak timing of fecal corticosterone secretion, moving from the light phase (ZT 9.33 h) in controls to the dark phase (ZT 18.4 h) in treated mice.
Original Statement
“The calculated time of the peak (acrophase) of corticosterone concentration was shifted from zeitgeber time (ZT) 9.33 h in CON cages, which was during the light phase, to 18.4 h ZT, which was in the dark phase...”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The phase shift is a direct quantitative observation from cosinor modeling of repeated fecal samples. The language accurately reflects the data without implying causation.
Evidence from Studies
Supporting (1)
The study found that mice eating a high-fat diet started releasing their stress hormone at a different time of day than normal — shifting from daytime to nighttime — which matches the claim.