People who eat fewer calories for many years have higher levels of a stress hormone called cortisol in their blood compared to people who don't restrict calories or who are endurance athletes, which might be a sign of a beneficial stress response.
Scientific Claim
Long-term calorie restriction in humans is associated with higher serum cortisol levels compared to age-matched sedentary individuals and endurance athletes, with mean levels of 15.6 ± 4.6 ng/dl versus 12.3 ± 3.9 ng/dl and 11.2 ± 2.7 ng/dl respectively (p ≤ 0.001), which may indicate a hormetic stress response.
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 study is observational and only shows association, so 'associated with' is appropriate. The claim correctly states the finding without implying causation.
Source Excerpt
“Serum cortisol was higher in the CR group than in age-matched sedentary and endurance athlete groups (15.6 ± 4.6 ng/dl versus 12.3 ± 3.9 ng/dl and 11.2 ± 2.7 ng/dl, respectively; p ≤ 0.001).”
Evidence from Studies
Supporting Evidence (1)
The study measured serum cortisol levels in CR subjects versus controls and found statistically significant higher levels in the CR group. The hormetic stress response is a theoretical interpretation of the finding.
Long-Term Calorie Restriction Enhances Cellular Quality-Control Processes in Human Skeletal Muscle.