The Study
A high cholesterol diet increases serum estradiol in female rats with lower energy availability following a treadmill training program
This study showed that when rats ate more cholesterol and ran on a treadmill, their hormone levels changed — but that doesn't mean the same thing happens in people. It's like saying a toy car goes faster on a ramp, but that doesn't mean your real car will too.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
When female rats run a lot and eat less, their bodies make less of a key hormone for periods. But if they eat more cholesterol without eating more food, they make more of another hormone that helps with reproduction.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 519 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This suggests dietary cholesterol might help restore estrogen levels in female athletes with low energy intake, but it's not proven in humans yet.
- 2Rats on high-cholesterol diet had 124% higher estradiol than controls and 171% higher than exercised rats on low-cholesterol diet.
- 3Leptin dropped 67%, body weight dropped 17%.
- 4Progesterone didn't change.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Sport Sciences for Health
Year
2025
Authors
Lyra R. Clark, Michael J. Dellogono, Thomas A. Wilson
Related Content
Claims (4)
In female rats undergoing endurance exercise and reduced calorie intake, eating a diet high in cholesterol does not change progesterone levels in the blood, but it does change estradiol and leptin levels.
In female Sprague Dawley rats subjected to endurance exercise and reduced calorie intake, consuming a high-cholesterol diet results in a 124% higher level of serum estradiol than a low-cholesterol diet and a 171% higher level than exercised rats on a low-cholesterol diet.
In female rats on a calorie-restricted diet, combining endurance exercise with dietary cholesterol increases estradiol levels more than progesterone levels, reflecting a specific change in how estrogen is produced or processed.
Cholesterol is required to produce sex hormones, and very low-cholesterol diets are associated with disrupted menstrual cycles and earlier decline in reproductive function.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.